Nano displaying folder icon and iTunes won't launch

'Kay, so I was attempting to update my first-gen nano's firmware (1.1 to 1.1.3) until iTunes crashed about mid-way through the update. I tried to relaunch iTunes but I get an error message saying that the iTunes library is on a locked drive and cannot be read.

I've checked in Finder and the entire iTunes library is still present in it's usual place.

I'm figuring I need to restore my iPod through iTunes, but if iTunes won't launch, is there any way I can restore the nano without it?

I haven't attempted it yet, although could a permissions repair fix this?

Thanks for any help.

UPDATE: A reboot fixed iTunes, I've just realised I'll have the opportunity to go to an Apple Store on Tuesday so I'll have a genius look at it.