i'm trying to create a filter, using fluent nH (1.2) automapping with nH 2.1.2.
I've followed the example here, but I keep getting the exception:  
filter-def for filter named 'DateFilter' was never used to filter classes nor collections..  
the filter class:
public class DateFilter : FilterDefinition
    {
        public DateFilter()
        {
            WithName(Consts.FilterConsts.DATE_FILTER)
                .AddParameter("date", NHibernate.NHibernateUtil.DateTime)
                .WithCondition("DATEPART(dayofyear,EntityTime) = DATEPART(dayofyear, :date)")
                ;
        }
    }
and in the mapping override:
mapping.HasMany(x => x.Stuff)
                .LazyLoad()
                .ReadOnly()
                .ApplyFilter<DateFilter>();
here's my configuration code.
Fluently.Configure()
                .Database(MsSqlConfiguration.MsSql2008
                .DefaultSchema("dbo")               //set default schema to enable full-qualified queries
                .AdoNetBatchSize(batchSize > 0 ? batchSize : 1)
                .UseReflectionOptimizer()
                .ConnectionString(c => c.FromConnectionStringWithKey(connectionStringKey))
                    .Cache(c => c.UseQueryCache()
                                    .ProviderClass(
                                    isWeb ? typeof(NHibernate.Caches.SysCache2.SysCacheProvider).AssemblyQualifiedName //in web environment- use sysCache2
                                        : typeof(NHibernate.Cache.HashtableCacheProvider).AssemblyQualifiedName //in dev environmet- use stupid cache
                                    )) 
                          )
                 .Mappings(m => m.AutoMappings.Add(
                    AutoMap.AssemblyOf<Domain.Entity>(cfg)     //automapping the domain entities
                    .IncludeBase<Domain.SomethingBase>()               //ensure that although SomethingBase is a base class, map it as well. this enables us to store all Something sub-classes in the same table
                    .IncludeBase<Domain.OrOtherBase>()    //create a table for the abstract 'OrOtherBase' class
                    .UseOverridesFromAssemblyOf<MappingOverrides.MappingOverride>()
                    .Conventions.Add(DefaultCascade.All())      //make sure that all saves are cascaded (i.e when we save a zone, its queues are saved as well)
                    .Conventions.AddFromAssemblyOf<IdGenerationWithHiLoConvention>()
                    ))
                 .Mappings(m => m.FluentMappings.Add(typeof(DateFilter)));
if I move the line before the automapping part, I get the exception:
 NHibernate.MappingException: filter-def for filter named 'DateFilter' was not found.  
can anybody tell me what I'm doing wrong?