Vista - Help with Vista 64 and Corel Paint Shop Pro 12.5

I am currently running Vista 64.

I downloaded and have been succesfully using Paint Shop Pro 12.5 - Corel indicated that it was the only version that would work with a 64 bit operating system. Suddenly the program won't respond. I've researched and used every fix I could find and still no luck.

My question is two fold. First has anyone else ever run into this and what they might have done to fix it. OR...two - I remember reading that other versions of PSP can be tweaked to work in Vista 64 mode but I cannot remember where. Does anyone know anything about that?

FYI - I have Norton 360 but applied the patch and the program worked before.
I have applied the fix for the conflict between the most recent MS update
that wasn't compatible. I've done a full virus and spyware scan.

Any help would be greatly appreciated