There are two KB articles regarding this issue:
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q317852
http://support.microsoft.com/?kbid=827714
The first one suggests to install SP3 (which you installed already), the second suggests a post-SP3 hotfix (build 8.00.0857 or later). You can download build 8.00.0878 from:
http://support.microsoft.com/?kbid=838166
What version do you have now ? (Run SELECT @@VERSION to find out).
In what circumstances do you encounter the problem ? If the first KB article is closer, then it's possible that the table is already corrupt; installing the latest version will not repair the table (it will only prevent corruption to other tables). In this case, I suggest that you copy the data to a temporary table, re-create the corrupted table and copy the data back into it.
Razvan
PS. I did not encounter this problem myself, my advices are based only on reading the KB-s.