I'm the same, or similar at least. I can't play iTunes purchased music on ipad2 if soundcheck is on, it looks like its playing but no sound from speaker, headphones work though. Ripped/stolen tracks work fine too. maybe differently to your problem I can simply turn soundcheck off and all seems to work fine.
On a side note, my iphone4 keeps giving me two notifications from last Thursday at random times, I've already dismissed and responded to these notifications (eBay and Facebook) but they keep popping up randomly as banners and then in notification centre.