3 GS weird volume issue

[brentg33]

So i am at work listening to some music when all of a sudden my volume goes down to nothing on its own. kinda of like when you get a call or email/text...but i didnt get any of thoes. when i tried to raise the volume up via the side buttons, the volume meter that shows up on the screen woudl just flash oddly. when i would slide the volume up on the screen, it woudl just slide right back down to nothing on its own. I reset the phone (which took longer than normal) and now everything seems ok...it was kind of like a got a call but they hung up fast locking my phone? anyways....just wondering if anyone else experenced this before.