In the normal course of events the statistics for SubText are kept up to date; but if you're messing around with the database they can get out of whack. In order to recalculate everything you can run the following SQL commands.

set nocount on
declare @Id int
declare @BlogId int
declare @EntryId int

declare entries cursor fast_forward for
select Id, BlogId from subtext_Content

open entries
fetch next from entries into
@Id, @BlogId
while @@fetch_status = 0
  execute subtext_UpdateFeedbackCount
  fetch next from entries
into @Id, @BlogId
close entries
deallocate entries