Bold 9900 microphone issue

So about 3 days ago my 9900 packed in and I could no longer use vlingo, send voice notes and when calling/receiving calls the other end wasn't getting any audio what so ever. I ofcourse presumed this was hardware so planned on taking it back to retailer in the week. Before doing this I decided to put the new OS from WIND just to see what the battery was like, after the update was complete the microphone started working again? Calls.. voice notes.. vlingo all working. I wake up today having done nothing to the phone aside from charge it and now the microphone is not working again?

Any reports of this anywhere else? Suppose the best option is to return?

You had the official OS and the microphone took a dump - you loaded another OS and it started working for a while.....then dumped again. I would have already exchanged it by now. I would recommend you re-install the official OS it shipped with. Most reps don't check, but just in case. ;)