XAV2001 Stops printing

I have two XAV2001 units that have been working perfectly on my network via my Netgear Router. Recently all printing from 6 laptops, two tabs and several other devices ceased to work. I can get to the web page of the HP printer and print built in pages, I can connect via an ethernet cable directly and print OK but cannot print through the powerline units. I have reset the units, applied security and can see them in NetGenie. When I attempt to print through them all signs are that it will print but the job eventually times out and errors, all this is using the same driver and cable that works when connected directly from a laptop. LED's are correct and data lights flash with net activity.....

Any ideas gratefully received! :confused: