Mic not working on Medusa Progamer

Hi,
I've already returned one Progamer because the mic suddenly stopped working, tried to install the replacement thru sound options in Control Panel, but with no luck.
Without the DB boost box checked i get no sound from the mic, with DB boost checked all i get is a continual roaring, which gets a lot worse if i place my hand on mic where it joins the headphones?????
Thought it might be a problem with the sound card (Audigy2ZS) so uninstalled the Audigy2 and went with the onboard Realtek AC97 (always disabled when using the Audigy) but no joy with that either.
I've read that some components could cause problems if they were too close to the inline amp, so everything got moved around, no good.
Tried using the mains adapter and the USB, still nothing.
Any help would be appreciated, or it could be just another broken mic.
By the way, as soon as i swop the Progamer for my Logitech, the Logitech's mic works fine.

No, never got the mic to work, had to return it to get a refund.
Since i had two mics that never worked properly i'm assuming that there is a hardware problem with the mics, which, is a shame, as the headphones sound wise are top quality.