My problem is very similar, my mic doesnt work, not the recorder neither in callings. But really isnt the mic itself, the mic is working i tested it in another phone, it is ok. Moreover i changed the mic in the mokia 5200 but stills without working. Someone told me its a problem of codecs of sounds. with some code (asterik-number-code-number) is deactivated and activated the mic as it happenss in many models of many brands of phones. Ive searched in blogs and forum for codes to activate the codes, so i got the *(number)3370(number) andother ones, but they dont activate the mic. Im ready to try flashing the phone, erasing the software and loading it again. Perhaps it could serve......