I hate to be that guy but we've got someone having trouble with Spring 103. I only ask because I know I've seen this problem and the solution before but I can't re-find it.
Tried setting AdvMapShading and AllowDeferredMapRendering to 0. Didn't seem to fix it.
It would be much appreciated if someone could remind me how to fix this.
I didn't manage to get an infolog from him, I'll see if I can remedy that. I do know he's using Radeon graphics.
Basically he's just installed, downloaded the map etc. and this issue showed up. That's about all I know.