On incoming call after "Slide to Answer" I can't hear anything.

[WooTek]

Whenever there's an incoming call I try to answer it the phone displays the call duration but I can't hear anything...so I have to hang up and redial this happen very often. I'm not only one with this issue...I have the Windows 7 Fantasy theme running but I really don't think this is cause of it...one of my friend have no problem with the earpiece issue running the same theme but he's on at&t and I'm on T-Mobile. Does this have anything to do with Ultrasn0w? cuz I'm pretty sure it's not the theme, I tried jailbreaking using Redsnow and had encounter the issue so I restored the phone and jailbroke it by using Purplera1n and stll samething.