That's clearly the same problem, with UT2 overflowing Simconnect with commands.
We ARE investigating the chance to make the ground using the same method (so, fully 3d, with shaders, etc) but not dependent of Simconnect, but we are still working on it, because it would require some hacking, but it might be possible that the "hacked" version might end up being more reliable than the "official" Simconnect.
I figured it was simconnect related.
The thing that I never understand with simconnect however, is why I can start at another airport with everything running and fly to DFW and its fine, but if I start at DFW fly somewhere outside the 16nm range and then return its not ok. I would assume that it would reset like it would if I had started else where. It's almost as if simconnect isn't letting go of the old informantion or something.
Oh well, I will wait and see if the other version your working on works better.