I'm having similar issues, i7-2600k @ 4.2, 16gb vengeance RAM, GTX 560. Max settings, FPS between 90-130. Seems to jutter a lot when either red timers are used, filters, block breakers, recycler and such all do same thing. FPS doesn't change, and audio for these is stuttered as well. I've turned everything down to lowest setting and still happens. At a loss here too. Not the only one as well, group of 3 close friends all experiencing the same thing. Any suggestions?