Problem with Next War Mech Graphics

[hankscorpio]

I run on a really old machine (video card is an ATI Radeon 8500DV with only 64MB) but usually, with time and more patience than I really have, I can play Civ4. I have been playing the Next War scenario the last few days and I have an odd problem where my mech graphics seem to be messed up. Most of the time, mech units are invisible (no units visible, just a flag). Weirder still, other units (notably the stealth bomber and missile cruiser) randomly show up as mechs. While it's pretty hillarious to watch a mech dragged along the path of a recon route or bombing run, I can't imagine that's how things were intended.

Has anyone else observed this problem or is my install somehow whacky? I can post screen shots this evening if nobody has seen this before.