Googlade lite och på Pro Tools hemsida säger de att man skall formatera för OS X i "journaled" form = HFS+.
Formatting Instructions - Mac OS X
Supported formatting utility: Disk Utility, included with Mac OS X
Open from the following location: Applications->Utilities->Disk Utility, or in the Apple Menu when booted from the OS X installation CD.
From the list of drives on the left, select the actual drive (the one on top, with the GB and drive manufacturer listed) rather than the user defined name of the drive below it.
Choose either the Erase or Partition tab
Choose Mac OS Extended (Journaled) - also known as HFS+
If you plan on using your drive on both Mac OS 9 and Mac OS X, check the box next to "Install Mac OS 9 Drivers".
Inte för att detta precis svarar på din fråga, men pekar det dock inte mot att det du hört torde vara felaktigt?