Well it sounds like a corruption problem. If you are conidering professional recovery then don nothing. You can try data recovery software Recuva http://www.piriform.com/recuva is free. TestDisk http://www.cgsecurity.org/wiki/TestDisk might fix it. sometimes booting from a Linux Live CD will give you access to copy the data off. You just learned the hard way to never trust important data to just one drive no matter who makes it.
Joe
