"THE LEOPARD ATE MY DINGOS!"
Once upon a time, my G5 was happy... and then I installed Leopard and the leopard ate my dingos! I have the G5 Jive with three internal Seagate 750 GB drives utilizing a Sonnett Tempo Sata X4i and my drives all freaked out- Warning messages stating I should pull all my data off as these drives were failing. Disk Utility First Aid warned: "Invalid Node Structure-Volume Check Failed".
Of course I did disk permissions & repairs prior to the OS 10.5 install and disk utility stated all my drives were "ok".
After a restart- no drives appeared except my Macintosh HD. I tried the competitions drive repair/recovery product that everyone at the Apple Store claimed was great... but it failed.
Then I googled Mac drive failure and up came Prosoft's Drive Genius. I knew of Prosoft because I had to use Data Rescue a while back and it worked perfectly.
Knowing that it was the same programmer/engineering folks I took a chance. Drive Genius worked wonders on rebuilding my directory and all my dingoes are happy and healthy again.
I'll tell everyone I know to use the best, Prosoft, and forget the rest. I'm a Prosoft customer for life!