>I have a network using Windows Server 2003 which was just installed a couple of months ago. We are having strange lockup problems on several machines. A VFP 9 application used inoffice will periodically lockup in a strange way. Typically the lock up occurs when the application is reactivated from the taskbar or receives focus again. Other applications will run. Killing the application in the task manager does not kill it. Killing the process in the task manager does not kill it. There is no network traffic and cpu use is between 5-11%. The only way to get out is to reboot the machine. On vista machines the entire program seems to go into disabled mode.

This is a SWAG - I had the same thing happen previously and after verifying the network cards weren't going asleep and everything network related under the sun was ok, completely removing the printers and their drivers and then installing different drivers made it go away. Does it happen only when the computer goes into standby mode or there is no activity for awhile?

Make sure everything in your app including runtimes and app and data is excluded from any virus checking, windows defender and anti-malware programs and see if it stops as well.