I've already solved this problem but I want to understand what could have caused the issue.
Client was running Windows 2000 prof on a SFF Compaq P3 computer
Client introduced an HP multi-function printer via USB to a HUB which was already connected to a Canon BJ printer and Mustek Scanner. As soon as she did that both the Canon Prntr and Mustek Scanner stopped working.
When a printjob was sent to the Canon only blank pages were printed. And the scanner failed to scan.
When the Canon was disconnected the HP and Scanner worked fine.
There was enough ink in all the cartridges. The printer was setup correctly as it had worked fine until the HP was added.
Any thoughts welcome.