I have been playing some LAN games with my brother using this build and I'm running into a few strange problems. If I host off one of my computers, FS2 locks up on the host machine (game freezes, with no mouse movement possible; the client computer is fine) in some situations. I haven't found any common factor in the crashes, but one place where it was consistently occurring was if I hosted Rebel Intercept (m-04b.fs2) and commited while the other player was still in the ship or weapon selection screen. I have had it occur both ingame and during briefings though. It's not a complete system crash, as I can alt-tab and close down the FS2 process. What's really puzzling is that hosting off the other machine doesn't seem to exhibit any of these problems.
I can try hosting using a debug build if that will help. Do both players need to use debug builds in this case?
The other issue is that the music and many of the sounds stop playing after going through a few missions. The sounds work fine for the first one or two missions, but in any subsequent missions the game stops playing music and starts dropping a lot of sounds (can be gunfire, engines, voices, etc.), both in briefings and during the game. It's not that specific sounds are blocked out; when firing a Maxim for example, I hear the sound once in every three or four shots. Also, if I die and respawn, the music briefly starts up again and inexplicably fades away after a few seconds. This happens on both computers, although not necessarily simultaneously. I am using the "generic software" setting on both of them.
None of these issues are present in singleplayer on either computer, by the way.