No sound during calls (iPhone3g)

[Gitgat]

ok very very strange issue that has survived two restores and i cant seem to fix.
ALL of my sound works correctly except during phone calls.
Sound works fine during skype, voice mail, games, music, video.
but the speaker, headset (wired) and receiver do not work doing calls.

I have restored twice, without restoring the backup. once from regular mode once from DFU. no dice.
I've tried the whole headphones in and out trick but that is defiantly not the issue as skype and games are still going though the correct speakers.

Any suggestions? if not i have an appointment with apple on Monday morning.

 

[OlgaJ]

I was on a 2 day road trip from Dallas to Breckenridge. First day I had no problems. Second day, took me a while to figure it out, speaker and earplugs worked, but earpiece did not. All data worked fine.

Stopped at the Apple Store in Colorado Springs without appointment. Waited almost an hour till someone checked my 2month old iPhone out. First thing they did was check for blockage in earphone plug; second, they took the phone in the back to clean it out inside. That didn't fix the problem so they told me they would do a "display replacement". That process would save my data but hopefully would fix the problem. That didn't work either. So in the end they replaced the phone.

Just make sure you have sync'd your phone before going to the Apple Store.

I sync mine with my laptop which I had with me, so I restored everything once I got to my destination.

 

[snwcrshx]

I have this problem very occasionally, and it is quite odd. Maybe once every week or two I'll get a call and the caller cannot hear me and I cannot hear them. I power down the phone and turn it back on and all is well. Kinda worried that while it is an infrequent quirk at the moment it will bloom into a larger problem in the future.

Think AT&T/Apple would do anything to replace the phone at this point (3 months since purchase) since the problem is very difficult to reproduce?