Its DB2 v8.2 on Windows 2003 server.
The db2diag.log does show any entry at the time when online screen is accessed. Even the Event Viewer does not show any error or information.
Bufferpool sizes are same
Is the application on the ssame server as DB2. are they both(Production and test) behind the firewall..
Did u check the application configuration on both the boxes same.I dont about this application. Once we also had the same issue..but it wasnt DB2 ..it was some application configuration parameter.
Hope this would help.