This is where I started last March - the app was originally purchased as a download, my off-hand guess, sometime in 2008. It was first installed on hardware that was replaced last march (the re-installs were attempted on a new MacPro nehalem model). That's when the error 18 messages first began to appear. I went round and round with Corel tech support then about un-istalling, re-installing, running it as a Rosetta app, etc., etc., until it was taking up more time than it was worth; I felt like a beta tester - several hundred $ for the purchase of the app for an un-usable one on new hardware. So I just let it sit while watching rss feeds about others having the same problem, hoping to see a solution - never did. The present service pack recommends trashing the application from the application folder and Corel files from the user's library's application support folder. This was done. Still does not work, and now, since the trash was emptied per the service packs instructions, I don't even have a non-functioning application file to put back in the applications folder.
Next idea?