I also had the radio app installed and then noticed that the mic was broken. But I also installed other apps, thus, I can not tell which caused the problem...
if mine is defective tomorrow
i'm just going to return it and get full refund
so here's our journey so far with the N900
pre-order -> wait -> more wait -> order cancelled by nokia -> re-order -> wait -> more wait -> order decline by bank -> re-order -> wait -> phone in hand but can't make calls
great, if mine is defective as well, i'm going to ditch Nokia
i had the N97, that was a big disappointment, really look toward for the n900 and now this
Exactly my experience!
I'm now at the stage of having an RMA number but no mail which has the full details to return the brick...