short lock-out when usb printer turned on

hi,
i have a shuttle xpc ST61G4 and i just got a cheapy HP printer (PSC
1215), and it works fine. but when i turn it on, it sometimes locks
out the system for about 7 seconds, and my wireless device may
disappear from the system (internal usb). so i lose my internet
connection and sometimes have to do a scan for hardware changes to get
the device back. the behaviour is sporadic so it's hard to pin down.
does anyone know how to avoid this?
i looked at the properties of my 3 usb hubs, one of them has full power
usage from the internal card reader, the other has full power usage
from the wifi card, and the other has 400ma to spare with the printer
and mouse attached to it. so i presume the usb hub with the printer
isn't overloaded. i checked the cabling and it seems ok.

thanks for any tips
tim