Comment 26 for bug 296710

> It's even simpler than you suggest.
> Simply add ehci_hcd to /etc/initramfs-tools/modules
> without changing anything else.

This worked like a champ for me. added the line then regenerated the initramfs, no more problems.
I've got kubuntu installed on a USB stick, so it was painfully obvious that i was in usb 1.0 mode for awhile... good to actually have transfer rates back.