Frequent "Error Executing Database Query" errors?

I am getting frequent "Error Executing Database Query. Timed out trying to establish connection" errors after upgrading our server to version 7. These errors only occur with applications that use Access databases and eventually cause the server to freeze up and I am forced to restart the ColdFusion service.

Any ideas on what might be causing this issue? I have applied all the hot fixes, updaters, etc, and updated the JDBC drivers and yet this problem still continues. Thanks.