At the end of finalizing my disc in the Sony Handycam Camera I received a disc error, all was working fine up until then. Camera is a few months old. Can I somehow retrieve the data off the disc? It won't let me unfinalize or read it from the computer. Help!

Have you tried something like this?
PC INSPECTOR smart recovery (http://www.pcinspector.de/smart_media_recovery/uk/welcome.htm)