[insomniaprincess]

I have no dongs but I had a mic problem and so far at least 3 other ppl have experienced the same thing and my solution worked for them.

(All of our mics worked w/ Windows controls/testing but not in game/Vent/TS/Skype/etc)

I went to my TF2 settings, switched to speakers then back to headset and then it started working again.

Again, if this isn't your problem, that's not going to help you much but if you've tried everything else, may be worth a shot *shrug*