Sorry but I and all the other Moderators/Admin do not have any inside knowledge or contact with developers or people that troubleshoot and provide fixes, at Corel.
One thing to note is that Cool 3D, including Cool3D PS is being discontinued. So I doubt there are any personnel still working on the programs. See official announcement
HERE
Are you running Vista 32 or 64 bit? I have managed to get Cool3D PS to run quite well on my Vista 32 bit machine. I don't use Vista themes, but the Windows Classical, and select run as administrator.
As far as the 30 day trial only running 3 days then expiring, if the program interprets some action on the system that maybe an attempt to circumvent the 30 trial, it will expire early. The only way to start the 30 days again would be to reformat your hard drive. If you have access to another PC that the trial has not been installed on, you could install and try it on that machine..