I don't know...

I don't know where to start with this...

This has been a problem for the past few months, close to a year actually...

My headset is a Logitech USB Headset Model 200. I use the drivers it automatically has... Anyway, the problem is that while i have Ventrilo and Natural Selection (Half-Life mod... Also in other games, but i usually play NS) running... I can't use my in-game voice chat... Or if i have Natural Selection running, i can't join Ventrilo and talk or hear anything because it says, "No sound device found". I also found out that in Natural Selection, it says in console that it cannot run Direct Sound Capture. I don't know how to fix it...

Also... another weird thing is that sometimes (rarely for the past few weeks) it will either have a bubbly sound... as in a lag sound (Video has no lag).
OR it will wait a while with fine sound and not have a problem. Then all of a sudden it will close all my sound completely and entirely. I also found out that if this happens... I cannot download, upload, copy, cut, move, delete, install, close vent, or listen to any sound on my computer whatsoever... BUT, i can still talk to people in vent. So i have to restart my computer when this happens.

I got a comment from someone to download a different driver, i don't know where to find one though.

I have tried...
Different USB port
No one talking in vent while in NS
-- That's it.

Any help will be great, and yes i know it is an interesting problem... I am not too much of a newb when it comes to computers... However, i don't know many things.