Logically connect/reconnect USB device

[NoOp]

Anyone know of a way to logically connect and reconnect a USB device
without unplugging/plugging or turning off/on?

Reason for asking is that VirtualBox (non-OSE) w/USB support is great.
However, as once you've assigned the USB port to a VB guest machine (ala
USB printer), use it, then release it, you can't get the device back on
the host (Ubuntu) unless you unplug/plus / turn off/on again.

Problem: I bring up VB & turn on a Win2K VM. I then logically attach my
standard USB printer to the VM, use it for awhile, then logically
unattach the printer. Switching back to the host, Ubuntu can no longer
find the printer unless I turn the printer on/off or unplug/replug the
USB port.

I'd like to find a way to do this logically so that when I go back to
Ubuntu from the VM the printer is then again available. Is there an
init.d or polling command that could do this via software?