I Just installed the 5.0.0.4 Firmware in my Z3100 and noticed that I when using Canvas I can now after printing an image either hit the cut button a few times to bring the canvas forward through the printer or just lift up the lever and then pull it through to get enought blank canvas to cut it off and then manually roll it back to a reasonable starting point and close the lever. The printer will then check the canvas, eventually leaving the edge where I placed it. With earlier firmware it would sometimes retract the canvas right to the edge or pull it all the way out of the printer.
This is a good improvement. I wish HP would reprogram the up and down arrows above and below the OK button to just move paper forward and back through the printer when no menu item was chosen. I've never had a large printer that didn't have this function.