Sound Problems - Replacement Issue

I posted this in the other forum, but there is never any activity in there. Maybe you guys can help me out.

Yesterday(for the 2nd time), I realized that my phone had no audio through the speaker or microphone. I couldn't hear anything when I call out or recieve a call; they couldnt hear me either.

I read somewhere about plugging in the headphone jack, and then unplugging it. That didn't work.

I then called AppleCare, and it all the sudden started working while I was on the phone with them. They set-up a time at the Apple store tomorrow morning to have it looked at and possibly replaced.

The problem is that I am flying out on business tomorrow night, and can't afford for my phone to be going haywire. If I take it in and the problem isn't there anymore, what can I do. I know it will happen again, because its happened before....

Does anyone have any suggestions about what to do?????

Thank you all soo much.