click run and....nothing

Question

I have a program which I haven't looked at in a couple of months. suddenly when I run it the IDE goes into run/debug mode, but the main form for the application never appears. it does the same thing on another workstation. the program compiles fine, and actually the compiled exe will run perfectly as long as I'm not executing it in the IDS. what gives? what should I look for to solve the problem?

thanks,