It appears my headset seems to developed a fault where the microphone isn't working correctly. I assumed that maybe it was the detachable microphone so I've bought another one and people still can't hear me. Further more, the left ear piece (same one where the microphone connects) has started to give me intermittent sound problems where it cuts out periodically so there definitely something a miss.
So if one of you guys could look over this I' appreciate it.