The manufacturer of the board makes next to no difference (unless they've added some 'extras', eg. BE6). The chipset is important, I'm using a standard Intel BX based board, and have had no problems or issues with it at all.
Since my SB Live works perfectly under the Win9x kernel I see no reason why people keep believing it's a hardware problem (SMP issues aside).
My boards linked up to a pretty decent hi-fi system too, so I might be hearing something you guys don't on your ****e PC-World desktop speakers.
It's down to one of two things I reckon, either a PCI latency problem (powerstrip FAQ has info about this) where Win2K is changing the latency of the video and/or audio boards. Or it's a driver issue, specifically in the buffer I think, might be a problem with DMA transfers.
Read my previous post on how to see if you've got the same problem. Going into the sound control panel to force a 'beep' works too, remember to try it with Winamp *paused* after a few seconds.
Sorry if I'm talking complete bollocks, I wouldn't be suprised if the different results are because of the many 'models' of SB Live!. Check out the .inf files, there's quite a few.