Background music becomes crackly and slow.

[god_king]

So this is a little on the strange side.

I recently installed a new life bar pack, and as a result, the MP3s playing in the background have become intermittently crackly and slowed-down. Mostly - though not exclusively - at the beginnings and endings of rounds.

What exactly has changed which causes this, and what can anyone suggest to get my background music playing reliably and well again?