invalid node structure, again.

Hi all,

Over the weekend my mac pro, after running disc utility, I find out has an invalid node structure. okay, I restore the drive from time machine. everything seemed to be fine. now today my machine was locking up again, running disc utility, I find once again "invalid node structure".

Is this a software thing or is the hard drive failing? If software what can I do to fix this so it does not happen again. thanks

With the evidence of a fresh install a few days ago, I would be backing up and getting a new drive - or call Applecare if you're still under warranty.

ordering a new drive now, thanks. that is what I was thinking, just wanted to confirm.