Good bet drive is toast
I have actually managed to lose 2 iPods in the warranty period due to drive failure. Have not been playing hockey with them, or anything else rough, but same symptoms. Sometimes a full resest of the iPOD (clear & reload my tracks) would give me some additional time, but seriously take it to an Apple Store/Center if you can. If you registered it online when you bought it, they should have a record of that, and shoudl not need the receipt. They just swapped my whole unit out. If you have to ship it past 90 or 180 days (do not remember which) it wil cost like $40, but not sure how warranty works overseas on a U.S. sold piece.