Concern with DirectX 9.0B

Hi,I am running FS2002 (soon to be FS2004 I hope) on a P4 2.8Ghz, 1Gb DDR400 memory and ATI 9800 Pro 256Mb running Windows XP Professional Service Pack 1 (nothing overclocked). I am also using the Omega drivers (Not the very latest ones, the version before this. From memory 3.5 and not 3.6).Also I did not reinstall the video drivers after installing DirectX 9.0b (have not had time to test yet if this will fix the problem described below).I was running DirectX 9.0a without any problems on this rig and recently installed 9.0b (after making a restore point first luckily) and experienced a massive stutter which started at various time intervals into the flight. Once the stutter started it continued for the rest of the flight. Also it was unusual in that the frame rate counter sometimes showed 29 to 30fps (I have it locked at 30fps) with no dips yet there was still a massive stutter that made it unflyable. Other times it would show 3 to 4 fps and stay there.After a process of elimination I have satisfied myself that it was 9.0b since as soon as I went back to 9.0a (using system restore) there has been no more problems.This is the first time I have experienced any form of severe stutter.I am just posting this in case anyone else has any unusual problems after installing 9.0b. As always YMMV (ie your mileage may vary).