Few years back I had to use a USB headset for the same problems but I had an earlier SB card in that system. Turns out the eairlier card was going bad so I replaced it with an X-fi card. That was with an earlier motherboard with a single core 3Ghz CPU. This issue with lockups during VOX has been a constant with the game as long as I've been playing over three different PC, 6 video cards and 3 different sound cards since 2002.
Some versions of the game or patches of versions have been solid. Some made pull my hair out or replace/upgrade the vido or sound card. Or just build a bigger badder computer all together. If Skuzzy describes his current game PC in an off hand remark and he's describing a completely new machine from just a few months ago and it's about time for a new game version. I know its time to get a bigger stick to beat the game with at my end........