when riding around I always have a rattling noise and figured out it was my gas cap by putting my hand on it and the noise went away. anyone else have this problem?

maybe putting a new gasket on would fix it?

I can't find my old post, but I had a similar issue where I swear the rattle was coming from the innards of the key tumbler mechanism.  if I lightly touched the key hole my rattle stopped.  I didn't try any other solution such as a new gasket and I still have a little rattle if I listen for it...sounds like BBs rattling inside my cap.

Anyhow, I just make sure to hold my cap on tight when locking it and it may have subsided slightly, but I also may just be getting used to it.

Try the gasket recommendation...can't hurt.