After installing an Nvidia GeForce 9500 GT video card I have had problems with choppy and halting sound in Return to Castle Wolfenstein. My sound card is a Sound Blaster Live 5.1 (Dell). The sound card has the latest drivers I can obtain as the card is a legacy card.
motherboard is a Biostar P4M900-M4, Pentium 4 2.6 GHz, 4 GB RAM.
When I played this game with my old video card, Nvidia GeForce 5200 FX(on my Dell Dimension 8300 motherboard), I had no problems with the sound while playing RTCW. I am wondering if there is a problem with the SB 5.1 drivers since when I use my onboard audio I have no sound problem. I have NO problem with sound on any other program while using the SB Live 5.1 card.
+1 to Kraynor for saying what I was going to say here.
Also, if your soundcard gives you issues but your mobo sound is working, just go with the mobo sound and save the calories from clicking "post" three times. There are starving children all over the world who would love to have those calories, and you're just wasting them.