I lost all the normal background music around the time I researched light plate armor. I reinstalled the game but there was no change. When I went to war, the war music was there. Also, the music that plays when you go to the option screen was always there. The music is back again now but as you can see in the debug file, it couldn't find the music files (it also includes an oom crash).

http://dl.dropbox.com/u/16872572/no%20music%20debug.err

This debug is from later in the game during the war, but I think I heard the normal background music again so I'm including it for comparison.

http://dl.dropbox.com/u/16872572/debug.err