The problem you guys are running into is a new Windows 7 "feature".
To accurately measure time in a Windows PC, software uses the QueryPerformanceCounter function. Many applications, especially games, depend on this Windows function to accurately calculate FPS as well as for many other timing purposes in game including sound.
The problem is that for many computers, this function in Windows 7 is now based on the clock speed of the processor. If you overclock in the bios and then boot up, this timer is calibrated and will work 100% correctly. If you use SetFSB or a similar program and you change the bus speed from within Windows, you have now just screwed up this very important timing mechanism. The number of applications that can choke after you do this is surprising, especially games.
I wrote a program called WinTimerTester to test for this problem.
What it does is it runs two different clocks in your CPU at the same time and compares them to make sure they are both running at the same speed. It compares the Windows GetTickCount function to the QueryPerformanceCounter function and within approximately 60 to 100 seconds, these two timers should be running at a perfect 1.0000 : 1 ratio.
If you overclock your CPU with SetFSB and WinTimerTester reports that these timers are not running at a 1.0000 : 1 ratio, that shows that you have this bug and you have also overclocked this important timer within your computer which can screw up a variety of programs in a variety of ways.
Luckily there is a solution to this Windows bug. Microsoft actually considers this a feature but for anyone that uses SetFSB on a regular basis, it's a big bug.
To fix this problem, open up a command window and type in this:
bcdedit /set useplatformclock true
You will have to exit the command window and reboot before this setting can take affect. What this does is it changes Windows so the QueryPerformanceCounter function will be based on a fixed counter that is not influenced by SetFSB. That one line of code should correct this problem and your games will run fine when using SetFSB.
If you ever want to go back to the original buggered up timer that Windows uses then open up a command window and type in this.
bcdedit /deletevalue useplatformclock
Once again, reboot and things will be back to the default Windows 7 timer. These two images should show you when your internal timers are broken and what WinTimerTester will report when your internal timer is fixed. This only applies to Windows 7. There is a similar fix for Windows XP so PM me if you need it.