You aren't very specific, having included no examples. But generally, it's due to the fact that it's an outdated build and unstable. Bleeding Edge is already up to 312 and has seen quite a lot of updates in that time.
Any issues you may experience have probably been fixed in newer builds, except geometry shaders (which you can read about by searching through the forums). We no longer support this build, so any issues you experience won't receive support.