Hey guys I have this weird sound problem that makes the song on the background lower than usual, but when I pause and resume the sound goes up and sometimes I can't even hear de guitar tone. I've messed around with the sound definitions but it didn't change anything. Anyone had this problem and knows how to fix it?

I've never had it, but I'm sure I've read about it.  Give the forums a good search.

I have this problem from time, and the only workaround I know of is to press ´escape´, wait a few seconds, and then press ´escape´ again to resume the song. Then volume usually goes back to normal.

You're not running the game on a battery powered laptop, are you?