USB Ports on LED Cinema Display- sleep issue

[ChrisdeG]

I just got a new MacBook Pro and 24-inch LED Cinema Display. I was planning on using one of the USB ports on the back of the display to connect a 1 Tb WD My Book drive as Time Machine backup. I've managed the first backup and everything seemed to be working fine, but occasionally when I wake the computer from sleeping I get an error saying that I disconnected my drive without ejecting it. Nothing has been disconnected, so I'm worried that the USB ports don't stay powered on when monitor/computer sleep, or that there is some other issue using a USB peripheral that is for all intents and purposes plugged into another USB peripheral. Has anyone else had these issues? I'd rather keep things connected the way they are right now- I have 4-5 other external drives I need to access on a regular basis, so going directly into the USB on my MacBook isn't an appealing option.

Thanks!

 

[brentsg]

Possibly it's a problem with the drive's internal firmware putting it to sleep? I am now using FW800, but when I had a USB drive attached to my 24" I had no such issues with Time Machine.