Sometimes when I navigate to an https site, my delicous toolbar favorite tags disappear from the toolbar. Any ideas?

I'm on Vista IE8. I'd prefer not to change browsers (most of my clients use IE so I feel it's good for me to be on it too.)
Here is a discussion thread at the delicious support forum.
Are you sure that you are logged in to Delicious at these times?
Does clicking on the checkered icon open your delicious page?
Since you refer explicitly to https page views,
I am wondering if this has something to do with the cookie access.
Its discussed on this thread.