Epson r3000 locks up USB ports on hubs

Not sure if this is proper forum but here it goes. I'm not even sure if it's an issue with printer or OS X. I emailed Epson support, but they were of a little help.

I have an Epson r3000 plugged directl into my Mac Pro running Mac OS X 10.6.8 Snow Leopard.

When I turn off the printer all USB ports on hubs stop working including the ports on my Apple Cinema Display. This inclues my keyboard/mouse hooked up to the USB ports on the display. They just freeze. However if I plug the mouse, for instance, direclty into the Mac Pro tower it works fine. I previoulsy had an Epson 2200 without any issue.

Any ideas?