WD Externel Hard Drive

( I hope that this posted in the right are.)

I am hoping someone can help me. I have a vanishing Western Digital Passport. (USB) It has vanished off my desktop and is not in my finder either. I can see it in my Disk Utility but it is grayed out. We have attached it to my BF’S PC and it shows up no problem. It will not mount on the MAC. It will flick showing to not showing in Disk Utility. What I have tried is:

Rebooting
I Checked that “Show all External Drives” is checked.
Relaunched My finder
Tried to repair / restore but would not let.

The one other time that this happened we had to wipe it clean and reinstall. But I do not want to do that (It kinda defeats the purpose.). I want to find out why it is doing this. It seems to vanish after I do system upgrade. I have heard with the USB contention sometimes there is not enough power and if you get a Y cable it helps. But that seems to refer to the laptops.

The specs on my system are:
IMAC Power PC G5 1.8GHz
MAC OSX 10.5.6 Leopard
Processor Speed 1.8GHz
1.25 GB DDR SDRAM

Oh and one thing – When it comes to this stuff I am a helmet wearing, short bus rider so please be kind.

Thank You

PowerPC Macs require the external drive to be formatted in Apple Partition Map and then Mac OS Extended (Journaled). To be bootable most PPC machines need the speed of a Firewire connection as USB, even USB2 is too slow.

Intel machines boot from USB2 drives just fine.