If I am right in thinking this is a timeout error coming from the database driver (you haven't included the error message), that the database server is there and that you are actually talking about VB _executables_ not scripts (which would be plaintext, not compiled) then:
- If you cannot access the code, you need to look at network bandwidth to the database server if applicable, then at the performance of the table during queries (has this just started to happen as you get more data?) - you should examine the indices on the table(s) involved and use SQL Server Profiler.
- If you can access the code, perhaps your query is not optimal.
From the info you've given, I guess the solution is down one of these paths.
R