Disk First Aid Not Repairing Drive

Question

I need to fix an issue with my external firewire drive and I need to know why Disk First aid won't repair the problem.
I have an IMac CoreDuo 20" 2GB RAM, 250GB Internal drive and 250GB External firewire drive (this one has the issue)
I executed a restart on my Mac tonight and when it came back up I recieved an Invalid B-tree node size on both partitions on the external firewire drive. Can your software fix this problem? The volumes won't mount, but Disk First Aid will see them.
Disk First Aid reports:
Verifying volume “disk2s3”
Checking HFS Plus volume.
Invalid B-tree node size
The volume needs to be repaired.
Error: The underlying task reported failure on exit
1 HFS volume checked
Volume needs repair
Verifying volume “disk2s4”
Checking HFS Plus volume.
Invalid B-tree node size
The volume needs to be repaired.
Error: The underlying task reported failure on exit
1 HFS volume checked
Volume needs repair
Ran disk first aid. Results above. TechTool Deluxe won' t look at the external drive. The Pro version of the software repairs external drives, but their site doesn't state whether you can fix Invalid B-tree node size errors. Formatting and starting over is not an option. I have data on their in which I captured last week on a business trip and was going to back it up tonight and ironically, this happened before I could.
I can't figure it out though. The drive didn't go through any crash or serious outage. I simply told my Mac to restart and this error appeared on reboot. I just switched to Mac as my main system about 8 months back. I have been using PC's for 20 years and never ran into a problem like this. It really concerns me that Mac file systems aren't reliable and if can't repair this, I will need to rethink whether I want to keep a Mac as my main system.
Can someone help me with this? I sure like using Mac and hope there is a simple solution to this.
I have tried booting from the Mac OS X cd as per Apples recomendations, but with no luck. I did use a trial copy of Data Rescue II just to see if it could see my data and it can, so I do have hope that this should be resolvable.

Answer 1

You won't believe what I had to do to get back some of my files, but here goes the explanation.
As I mentioned earlier, I used TechTool Pro 4.5.1 with no succes. I also used a tool called Drive Genius from Prosoft Engineering and it was not successful either. I did get some more error information when trying to repair the partitions with Drive Genius. Here are the messages I received:
Error : Invalid HFS+ signature found in the volume header (0000 - (n).
Error : Invalid HFS+ version number in the volume header (0).
Error : Invalid HFS+ total block count found in the volume header (0).
Error : Invalid HFS+ resource fork clump size found in the volume header (0).
Error : Invalid HFS+ data fork clump size found in the volume header (0).
Error : Unable to get the HFS+ volume header.
My only other option was to purchase Data Rescue II from ProSoft Engineering and attempt to recover the files I needed. I had a bunch of recordings I had made with ProTools that I had not had a chance to backup to another location yet.
It took a couple hours for the scanning processes and then the files were listed to recover. I selected the session folders and told it to recover. The file s were copied to my local hard drive and I was getting excited, until I tried to open one of the files. The wave files would not play and the PorTools session files wouldn't open. I was very frustrated since the file sizes seemed to be in line with the files were on the original drive.
What I ended up doing was, using Text Edit, I opened a known good .wav file that was created with ProTools and one of the recovered files that wouldn't play and compared the headers. It appeared that the recovered file had the data portion, but not the header. I copied the header from the good file and pasted it into the recovered file and saved it.
Was I surprised when the file played. Now, most of the .wav files I have done this with work with no problems at all. A few of the files have bad spots (bits) that added distortion to the clip, but I was able to import the files into ProTools and edit them out. It appears that the bad spots were additions to the file and did not overwrite any thing. So I just cut them bad spots out and I am going about my business again.
The bad new is I will be spending most of this weekend manually restoring these files. The good new is that I will get them all back. There has to be an easier way to do this though.
In Summary, the problem is not with the physical drive as a thourough drive scan says that the hardware and drive is okay. The problem lies in the Apple file system (HFS+) itself.
I sure hope this information helps someone out there. If anyone finds an easier way to fix this, please post it here and let everyone know.