Help! External drives dismount themselves upon sleep

I have two external drives, one Firewire one USB 2.0 (I have a PCI card for this installed) that seem to dismount themselves when the system goes to sleep.
George Fowler wrote on :

Greetings!

I bought a new 250 GB hard drive and installed it in my Quicksilver G4 867, and I took the opportunity to do a fresh installation of the system over the weekend, upgraded this morning to 10.2.8 (no problems with that). Starting this weekend (so still under 10.2.6) and continuing under 10.2.8 I have two external drives, one Firewire one USB 2.0 (I have a PCI card for this installed) that seem to dismount themselves when the system goes to sleep. And it gives me that irritating error message in the Finder about a missing volume. I have the preferences on Energy Saver set so that hard drives do not try to go to sleep whenever possible, although the system sleeps after 15 minutes. I can get the drives remounted by running Disk Utility twice (the first time it doesn't usually see any drives, internal or external; the second time it recognizes the external drives in question and they remount.

Actually, I'm not sure this is related, but I have also had two failures of the entire system to awake from extended sleep (such as overnight) since the reinstallation of the system, none yet since upgrading to 10.2.8. These required a hard restart, and after one of them I got a kernel panic early in the startup process (it started right up after that).

This is pretty irritating. Any suggestions as to why it might be happening and how I might be able to stop it?

Thanks in advance!

George Fowler