>>
>>Have you made any progress with your performance issues?
>*
>Since we could not figure out the cause of the problem, I decided to address the symptoms and make sure that all SQL queries /JOINs are optimized, which helped. The problem seems to be related to file locking (as soon as the 2nd user is on using the application, the performance slows down 10 fold, and it remains as slow that regardless of the number of additional users). It is an ongoing issue right now; I may come back here with more news. Anyway, what's puzzling is that we see this only at a couple of clients; everyone else is fine.
>Thank you all for your suggestions.

Please do come back if you find the differences between the clients that have no slowdown and those that do. We have seen the same sort of behavior in about the same environment.