Sharing with Facebook has the problem that it only accepts an url in the EXTRA_TEXT. The native FB app will then grab a text and an image from this url to compose the post. That's not a "bug" but the intended behaviour they give to the official app :-/
Take into account Twitter will only accept text/plain without any markup and with 144 chars at max.
I've made my own "Share" dialog to intercept all different behaviours and give to each target intent what they accepts: HTML, plain text, FB URL and Twitter short text.
Here comes the code:
public class ShareHelper implements AdapterView.OnItemClickListener {
            private static final String TAG = ShareHelper.class.getSimpleName();
            private Activity mContext;
            private Dialog mDialog;
            private LayoutInflater mInflater;
            private GridView mGrid;
   private ShareIntentAdapter mAdapter;
        private int mMaxColumns;
        private List<ResolveInfo> plainTextActivities;
        private Set<String> htmlActivitiesPackages;
        private String subject;
        private String textbody;
        private CharSequence htmlbody;
        private String twitterBody;
        private String facebookBody;
        public ShareHelper(Activity context, String subject, String textbody, CharSequence htmlbody, String twitterBody, String facebookBody) {
            this.mContext = context;
            this.subject = subject;
            this.textbody = textbody;
            this.htmlbody = htmlbody;
            this.twitterBody = twitterBody;
            this.facebookBody = facebookBody;
        }
        @SuppressLint("NewApi")
        public void share() {
            this.mInflater = LayoutInflater.from(mContext);
            final Intent sendIntent = new Intent(android.content.Intent.ACTION_SEND);
            sendIntent.setType(HTTP.PLAIN_TEXT_TYPE);
            plainTextActivities = mContext.getPackageManager().queryIntentActivities(sendIntent, 0);
            if (plainTextActivities.size() > 0) { 
                htmlActivitiesPackages = new HashSet<String>();
                sendIntent.setType("text/html");
                final List<ResolveInfo> htmlActivities = mContext.getPackageManager().queryIntentActivities(sendIntent, 0);
                for (ResolveInfo resolveInfo : htmlActivities) {
                    htmlActivitiesPackages.add(resolveInfo.activityInfo.packageName);
                }
                mAdapter = new ShareIntentAdapter();
                final View chooserView = mInflater.inflate(R.layout.dialog_share_us_chooser, null);
                mGrid = (GridView) chooserView.findViewById(R.id.resolver_grid);
                mGrid.setAdapter(mAdapter);
                mGrid.setOnItemClickListener(this);
                mMaxColumns = mContext.getResources().getInteger(R.integer.maxResolverActivityColumns);
                mGrid.setNumColumns(Math.min(plainTextActivities.size(), mMaxColumns));
                AlertDialog.Builder builder;
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
                    builder = new AlertDialog.Builder(mContext, AlertDialog.THEME_DEVICE_DEFAULT_LIGHT);
                } else {
                    builder = new AlertDialog.Builder(mContext);
                }
                builder.setTitle(R.string.text_share_us_title);
                builder.setView(chooserView);
                mDialog = builder.create();
                mDialog.show();
            } else {
                Toast.makeText(mContext, "No social apps installed to share ChurchLink!", Toast.LENGTH_LONG).show();
            }
        }
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            ResolveInfo info = (ResolveInfo) mAdapter.getItem(position);
            Intent intent = new Intent(android.content.Intent.ACTION_SEND);
            intent.setClassName(info.activityInfo.packageName, info.activityInfo.name);
            intent.setType("text/plain");
            intent.putExtra(Intent.EXTRA_TITLE, subject);
            intent.putExtra(Intent.EXTRA_SUBJECT, subject);
            if (info.activityInfo.packageName.contains("facebook")) {
                intent.putExtra(Intent.EXTRA_TEXT, facebookBody);
            } else if (info.activityInfo.packageName.contains("twitter")) {
                intent.putExtra(Intent.EXTRA_TEXT, twitterBody);
            } else if (htmlActivitiesPackages.contains(info.activityInfo.packageName)) {
                intent.putExtra(Intent.EXTRA_TEXT, htmlbody);
            } else {
                intent.putExtra(Intent.EXTRA_TEXT, textbody);
            }
            Log.d(TAG, info.activityInfo.packageName);
            ((Activity) mContext).startActivity(intent);
            mDialog.dismiss();
        }
        public class ShareIntentAdapter extends BaseAdapter {
            public ShareIntentAdapter() {
                super();
            }
            @Override
            public int getCount() {
                return plainTextActivities != null? plainTextActivities.size() : 0;
            }
            @Override
            public ResolveInfo getItem(int position) {
                return plainTextActivities.get(position);
            }
            @Override
            public long getItemId(int position) {
                return position;
            }
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                View view;
                if (convertView == null) {
                    view = mInflater.inflate(R.layout.griditem_share_us, parent, false);
                } else {
                    view = convertView;
                }
                bindView(view, plainTextActivities.get(position));
                return view;
            }
            private final void bindView(View view, ResolveInfo info) {
                TextView text = (TextView)view.findViewById(android.R.id.text1);
                ImageView icon = (ImageView)view.findViewById(android.R.id.icon);
                text.setText(info.activityInfo.applicationInfo.loadLabel(mContext.getPackageManager()).toString());
                icon.setImageDrawable(info.activityInfo.applicationInfo.loadIcon(mContext.getPackageManager()));
            }
        }
    }
Seems like some people wants the layout files too. Here are they:
dialog_share_us_chooser.xml
<?xml version="1.0" encoding="utf-8"?>
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/resolver_grid"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="center"
    android:clipToPadding="false"
    android:columnWidth="128dp"
    android:numColumns="4"
    android:padding="16dp"
    android:scrollbarStyle="outsideOverlay" />
griditem_share_us.xml (from own AOSP project):
<?xml version="1.0" encoding="utf-8"?>
<!--
/* //device/apps/common/res/any/layout/resolve_list_item.xml
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
**     http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
-->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:gravity="center"
              android:orientation="vertical"
              android:layout_height="wrap_content"
              android:layout_width="match_parent"
              android:padding="16dp">
<!--               android:background="@android:drawable/activity_picker_bg" -->
    <!-- Activity icon when presenting dialog
         Size will be filled in by ResolverActivity -->
    <ImageView android:id="@android:id/icon"
               android:layout_width="wrap_content"
               android:layout_height="wrap_content"
               android:scaleType="fitCenter" />
    <!-- Activity name -->
    <TextView android:id="@android:id/text1"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:gravity="center"
              android:minLines="2"
              android:maxLines="2"
              android:paddingLeft="4dip"
              android:paddingRight="4dip" />
<!--               android:textAppearance="android:attr/textAppearanceSmall" -->
</LinearLayout>