I have a new Photosmart 7520 and have this problem. Everytime I change from printing from the computer to making copies, the next time I try to print from the computer I get an error message - and - it won't print from the computer.
The message says something like Windows does not recognize the USB device, etc. In order to fix it I have to restart my computer AND unplug the USB cable and plug it back in.
I don't like having to do this every time I switch from printing from the computer to just making copies. Is there something I should be doing differently to prevent this???