Jon wrote this:
Maybe the program has been corrupted somehow or you have some virus or similar. Although rare, we've seen corruption issues in the past so now all parts of the program are digitally signed for your protection and to support Vista security and AntiSpyware protocols.
Please go to the Opus program folder, right click the program to access Properties. Check the digital signature is valid. If it is not valid then possibly something has corrupted the program in which case you should download the official digitally-signed version and reinstall.
If you still have a problem after this, please submit an official support request from the Support page on the GPSoftware web site with your registration details and we will investigate the matter further with you.