MBP17-08 : When running battery : USB, random device removal error

Hey everyone,

Has anyone else experienced this?

When I'm not plugged into AC -- I get random 'Device Removal' errors, wherein my external drives unmount and mount.

This specifically happens when my computer goes into sleep [screen black mode] or when the monitor dims and comes back on. It's very strange.

Are all the USB ports on the Macbook Pro 17" [late 08 version] have the same power/capability?

It's really confusing...

Thanks! MD