Yeah UAC does suck
Just disable the JSGME mods for now
There are a few others on here playing with Steam that seem to be ok - dont use Steam myself so not 100% sure whats going on there
http://www.subsim.com/radioroom/show...90&postcount=2
http://www.subsim.com/radioroom/show...ighlight=steam
http://www.subsim.com/radioroom/show...ighlight=steam
http://www.subsim.com/radioroom/show...79&postcount=9
Those above may be of some help