What version of KHPro are you running? You purchased the 4.008 upgrade in April, 2003. Please check and post back here. If you are running 4.008, I'll move this Thread to the right Forum so others with the same product can help also.
When in doubt, shut down your computer, wait 10+ seconds, restart and then try KHPro again. If it still has a problem, uninstall it and install it again, rebooting before you run it.