Good questions...should have included all of that in the original post:
1. iPhone 4
2. Firmware: 4.01
3. Jailbreakme.com
3. When I am talking on the phone and i want others to hear the conversation, I will press the SPEAKER icon on the phone menu...but now this does not work. The speaker icon indicates it has been invoked but no sound comes out of the speakers on the phone. BTW, I just discovered the same hold true when playing music....no sound out of the speakers on the phone....but there is sound in both cases with headphones on.
4. The silent button is not 'on'.
5. Apps installed: Cydia, Rock, many themes, Tetherme, 3G unrestrictor, Iconoclasm, winterboard, backgroundr