Argh, it's driving me nuts! The thing is finished after the best part of a year's effort, only to find that the moment I create what I believe a release version, it loses all the quality it had while developing.
Are you saying you developed it completely in debug mode? :O I only ever turn debug on when I hit a problem.Anyway, testing now...
[edit]Well, my monitor doesn't support 1024x768 so I had to test in 800x600. Everything seems pretty smooth to me - the movement of the floating cubes does seem to glitch very slightly, though. Nothing very bad - I doubt I would have noticed if I wasn't looking for it.
Have you tried turning off as many background tasks (AV, firewall etc.) and re-testing?