That's a lot of hours of my life that I'll never get back. Given that I'm still kind of pissed off about it I'll save the recriminations for later (suffice it to say that I'm glad I didn't try to go with MinGW in the first place - ancient msvcrt dlls do not play nicely with Coldest). About the only good thing that came of this was that I cleaned up some potential threading problems and got rid of some previously uncaught errors in the code (due to concept checks in STLPort and GCC 4.3) in my attempts to stop the MinGW build from crashing.
In any case, I ended up sticking with Visual Studio, but I'm now using 2005 since it still seems to be better supported and actually the STL in it is not causing me as many problems as the STL in 2008 did (why? No idea. Given what I thought my problem was in 2008 I expected the same or worse in 2005. Chalk it up as yet another unanswered question from this whole exercise). I'm still using STLPort though because it performs much, much better, even slightly better than the MinGW one did (when it worked).
Anyway, this means that Windows users will no longer have to wait minutes to load maps with grass, which means that hopefully I can start playtesting a little. Maybe we'll even have something playable by Mega LAN now.:-)