[Jeckel]

Well, do some process of elimination. Restore your device (normal Apple firmware) and see if music and such work there. Then QuickPwn (without updating a single thing or adding anything except your music), see if that causes a problem. Then update Cydia/Installer and see if that does anything. Then add things one at a time (checking each time if your music is 'gone') until it wont work.

I find it interesting, though, how you (and some others, no offense) think it's Cydia's fault, though you have more dangerous things on your devices (cracked apps).