Was your application installed via a disk or through a network image? If it was installed via a network image, and the server that housed that image is no longer available, you're going to have a hell of a time uninstalling. Sorry that I can't offer any specific advice on how to remedy the problem, but if you check with your IT person, maybe they can point you in the right direction.
Ross Kirby
Principal
Dynamik Design
www.dynamikdesign.com