disappearing external drives

[psp]

G4 Dual 867 2g OS10.5.4. I have 2 external drives (Lacie 200g USB • Western Digital 120g USB) that unmount unexpectedly, sometimes they remount. Any solution?

 

[Satcomer]

USB? Firewire? SATA external?

 

[psp]

Western Digital 120g USB external
LaCie 200g USB external

I'm running Leopard 10.5.4

Thanks for your help

 

[Satcomer]

Unmount the drive and disconnect them before doing this! Reset the PRAM holding the butoon down for THREE bongs before letting go of the buttons.

 

[DeltaMac]

Are both drives self-powered, or bus-powered?

Have you added a PCI USB 2.0 card?

Or, are you using the built-in USB 1.1, which would make for a horribly slow experience with large drives like that!

 

[psp]

Both drives are self powered and I have installed a USB2 card.
I will try the PRAM and let you know if it works.
Thank you for all your help!