I have the same problem with the game crashing when I try to use Planetfall. I've tried opening Planetfall v13 directly as well as trying to load it from the BTS mods menu. Also I'm running XP and have never installed a previous version of Planetfall. Installed the mod & the patch fine, and put the SMAC sound files in the correct place.
Please help, I was so stoked when I discovered this mod ._.