I dont think the version should have mattered.
One thing you could try, on the old powerbook, let it upgrade to the latest version of iPhoto.
On the new Mac, delete your photos out of iPhoto.
On the new Mac, make sure you have the latest iPhoto.
Connect the FW Cable
re-transfer the "iPHoto Library" from the old powerbook to the new Mac
On the new Mac, open iPhoto....
Logically..... that should work and it should have your albums and photos back how they originally were on the powerbook.
Good Luck.