XNA 4.0 runs at 50 instead of 60 fps.

Question

I'm experimenting a bit with XNA 4.0, following tutorials and creating very basic stuff (like a triangle and some lines ;-)). While doing this, I noticed that all my applications never run at more than 50-51 fps (with Fraps). It's not that I'm running heavy programs on a slow computer or graphics card (Ati HD4870), it must have something to do with XNA (games run just fine here).

Now, everything I read about XNA says that the default update frequency is 60 times a second, and I'd like to get that.

• It's the same in full screen as in windowed
• If I set SynchronizeWithVerticalRetrace to false or true: same
• If run the program without Visual Studio, I only get 41 fps
• When I override the update frequency by using TargetElapsedTime = new TimeSpan(0, 0, 0, 0, 10); the fps does go up significantly. I noticed though that this still isn't correct: the 10 means 10ms, yet I 'only' get 83 fps instead of 100. At 1ms I get 850 fps. So the deviation of what fps I get and what I should get is pretty consistent. It looks to me like there's just something wrong with the timing?

Anyone knows what might be the problem here and/or has suggestions to get a stable 60 fps?

Thanks!