Is this for new posts as well as "upgraded" ones?
Do the posts show fine when you are in the users blog?
THere is a setting in advanced options for each post (display on my sites home page), which could affect this, as well as a default for the blog under configure / post options / display...
Dan
Would it be possible to get a profiler trace of the query run for posts on your blogs default page?
it will look something like this:
declare @p8 int
set @p8=1
exec dbo.[cs_shared_Threads_GetThreadSet] @SectionID=-1,@PageIndex=0,@PageSize=15,@sqlPopulate=N'SET Transaction Isolation Level Read UNCOMMITTED
Select P.PostID From dbo.cs_Posts P right join dbo.cs_Threads T on (P.ThreadID = T.ThreadID) inner join dbo.cs_Sections S on S.SectionID = P.SectionID where P.SettingsID = 1000 and S.ApplicationType = 1 and S.IsActive = 1 and S.IsCommunityAggregated = 1 AND S.HubSectionID = 0 and P.ApplicationPostType & 3 <> 0 and P.PostConfiguration & 2 = 2 and P.IsApproved = 1 and P.PostDate <= getdate() Order by P.PostDate desc ',@UserID=0,@IncludeCategories=1,@IncludePageIndex=0,@TotalRecords=@p8 output,@SettingsID=1000
select @p8
You might also want to try running that against your database, and see if the posts you would expect to see are showing in the results.