Having problems with taking a call on my blackberry because the volume goes up and down on its own while I'm trying to talk. And the caller doesnt hear me. Any suggestions?

You can try "rebooting" the unit. While it is ON (yes, ON), pull out the battery and keep it out about 30 seconds.

Maybe it is your carrier and your location while using the phone. If a new phone, maybe it is a bad phone.

I have that same problem... same model phone and OS