Sudden problems with headset

A few days ago my mic on my headset started to play up. In games it wouldnt work & on TS it wouldnt work. The odd part was though that i could hear myself when i talked into the mic through my earphones(normal for me) and it worked fine for the BF2 mic setup.

iv checked all the settings and nothing AFAIK has changed, and as i said above, it worked fine a few days ago.

Something iv noticed is in my soundMAX centre (default controller for sound) there is a warning triangle which tells me my mic needs to be muted, but no reasons why - any ideas?

Its a sharkoon majestic 5.1 USB. My hi-fi is connected to the ear of my PC and the PC switches between the 2 depending on my USB headset being plugged in or not. Has worked for for 4+ months.

PC is e6300 & similar spec'd components accross the board. Im running off my mobo sound card.

any advice? cheers guys. :undecided