Whenever I am using my macbook on the go, the volume controls lock and it wont allow me to move it usiny ANY fasion. I tried going to system controls, keyboard controls and in the menu bar. The volume locks and the slider becomes grey on the menu bar and it wont let me move.

Also, i will be randomly playing a song, and it will stop for 5 or so seconds, then start again.

anyone else having this problem?
what gives?