Have a user where I just installed a new HP OfficeJet Pro 6970 via USB. Works for a day and then problem starts where printing anything produces black lines across the paper. I've tried changing usb cables, changing usb port on pc connected to from USB 1.1 slots to 2.0 slots, disabling anti-virus, rebooting to no avail. Copying on the AIO works fine. I've checked the event logs, but nothing really jumps out. Scanning can get bad as well. Seems to be some communications thing, but I don't know. it doesn't look like anything is starting up out of the ordinary that's interfering with it either. Only "fix" is to uninstall the drivers and accompanying HP software, and reinstall it from scratch. This only resolves it temporarily. Need help!