Did you check the fixed bug list yet? Was there a fixed problem that matched your issue? That would be what gives you the reasonable expectation of whether there was a bug and it has been fixed or not.
If not, I'd say it comes back to my original diagnosis: Operator Error.
Have you taken the project to another editor to find out if the issue lies with your computer, your software, your project, or you?
If all else fails, pack up your computer into a box. Carry it to the place where you bought it and return it. Almost everyone else knows what I'd say you should say then.