^ have you tried running Recount & Rebuild tool at the tools & maintenance section of admin panel
Quote:Recount and Rebuild
The Recount and Rebuild portion of the Admin CP allows you to recount the various statistics, counters, and attachment thumbnails. This corrects any synchronization errors that may have occurred. This includes Recount Statistics, Rebuild Forum Counters, Rebuild Thread Counters, Recount User Post Counts, and Rebuild Attachment Thumbnails.
Each (excluding Recount Statistics) allows you to specify the number of data entries to process in each page. If there are fewer than the number entered to process, only one page will be used.
To run, enter the number of data entries you wish to process per page, and select Go in the row for the item you wish to recount or rebuild. If more than one page is necessary, you will need to select "Proceed" after each page is run.