I just bought aliens of gold and i am experiencing a lot of sound problems. The music plays and the sound effects of picking stuff up seem to work without any problems but firing the gun and opining doors are not right. First of all the sound of the gun only plays like once every three shots (no lag, just missing) and opening doors is very crackeling. Also it seems that only once every few footsteps is played...
I tried to change some things in the setup file but that didn't help anything. Do you guys have any solutions?

what kind of hardware are you running? if you pc does not have a lot of speed or a lot of windows services doxbox will lag on sound emulation.

hmmm my pc is fine (runs crysis on high settings with good framerate) and i keep it clean so not many things running in the background...

The issue is that the game runs in a MS-DOS emulator called dosbox you could try downloading version 0.73 and copying the files in to the game folder and see if the sound emu works faster. is your windows X86 or X64. Dosbox actually runs faster on a x64 windows install than a x86 install.