fsx sp2 problem

hi I thought I'd have a change from fs9 and installed fsx + sp1 for the first time today and I must say I was impressed.I then installed sp2 (not acceleration)and the problems began.After sp2 I noticed the following ,apologies for the unscientific descriptions:1.)The textures surrounding the rwy(KSEA)are black for 2-3 seconds each time after loading.2.)When airborne the ground texture tiles around the aircraft 'bend' into place instead of snapping into place and the textures are very unstable.Frame rates drop also.I uninstalled sp2 and all was well again .I tried a couple of times installing /uninstalling sp2 and each time it was installed the problem returned.Unfortunately I need sp2 as some addons require it e.g Kaitak I believe which I can't do without,otherwise I would stick with sp1 only.I have searched but not got anywhere and if anyone knows a cure I would be very gratefulEDIT: XP Home, 7950 gt 512,2gb ram,e6850 core 2regards Jim