Specs:

MSI K8N Neo2 Platinum mobo, onboard Realtek AC-97 sound
AMD A64 3000+ (Winchester) at stock speeds
2x512 MB DDR400 RAM @ 3-3-3-8 (Infineon)
Windows XP SP2
Background apps: Avast! Antivirus, GetRight, Trillian, Winamp agent, Gmail notifier

I've been searching around the forums but didn't find anything that fixed my problem. Basically, both the music and the sound effects are sluggish, as if something was interrupting the sound card's work.

I'm running both the sound setup and the game through VDMSound. The setup utility autodetects a Sound Blaster 16 with the pre-assigned port, IRQ and DMA settings, and while other variations (SB Pro, diff. IRQ/DMA etc) work too, the stuttering is just worse with those.

I've tried changing around... well, just about anything. IRQ/DMA numbers, the sound output device, disabled EMS, and a bunch of other random stuff, to no avail.

I've enabled logging, and there are a bunch of these lines:

1Attempted to write to unimplemented mixer register (register = 0x3f, value = 0x63)
2Attempted to read from an unimplemented mixer register (register = 0x3f, value = 0xc0)

The numbers are always the same.

Through DosBox, setup autodetects a Gravis Ultrasound soundcard and plays the test samples perfectly. However, in the game both the video and the sound are extremely laggy.

Any ideas how to solve this?