Hard drive failure to load after being connected to NAS

Alright so I have this 500 gig western digital HD in an external HD enclosure. Anyways it' all been off and on. But recently I've been putting everything important school work, back ups of my site everything. The other day I walked into the room where the base station was and I noticed the light was Amber. So I unplugged it and tryed to power cycle. Nothing still yellow, I did a firmware yesterday and the one update was released nothing. When I started the airport utility it told me the attatched drive had errors that needed to be fixed and to connect it to the computer. As soon as I did that the base station went green. When I connected the HD to the mac it failed to load. I tryed to repair it from utilities and got the following error messages

Verify and Repair disk “disk2s1”
Checking HFS Plus volume.
Invalid node structure
Invalid B-tree node size
Invalid node structure
Invalid B-tree node size
Volume check failed.

Error: The underlying task reported failure on exit


1 HFS volume checked
1 volume could not be repaired because of an error

Click to expand...

I also tryed to repair it via drive genius and the same thing occured nothing. I want to try data rescue but I do not have another hard drive that big to use a temporary storage.

Get a copy of disk warrior, it works better than the disk utility application.

I tryed connecting it to an old G4 which has it on there it didn't even detect it. =(

I'm wondering if it's worth trying to connect it to a PC.
Right now i'm scanning it in data rescue II.