I've noticed that every 4.5-5 seconds, I'm getting a pause for about 1/10th of a second ever since I started using MyGUI. If I watch the FPS in gDEBugger, it runs smooth at about 300fps, then tanks to 0 for a few frames before jumping back up to 300. I'm using MyGUI 2.3.0 with OpenGLPlatform in my own engine. The pauses happen in both debug and release (although in release, they seem to be more like 3 seconds apart). I just commented out my MyGUI code just to make sure and the pauses went away, so it is definitely something going on with MyGUI. Is there something going on in the background that I could turn off that would get rid of the pauses? Maybe it's flushing to the log file or something? It doesn't really hurt my development, but if I ever expect anyone to play anything I make, I can't have consistent framerate hitches . I don't really have any tools to try to track it down with and it does it even if all I'm doing is displaying a single button. Any ideas what it might be?