Audiovox SMT 5600 / SPV C500 (HTC Typhoon)

I think the internal antenna has become detached on my phone. The reception has declined (especially when walking or otherwise shaking the phone while talking), and there is a rattling when you shake it back and forth. Has anyone experienced a similiar problem, or had any experience dealing with Audiovox's warranty (it is a 1 year warranty)?

I don't really consider myself an abnormally tough cell phone user, but it is showing some wear and tear and i'm sure i've dropped it once or twice.