I'm helping a friend set up her new wireless printer to interface with her Mac Book Pro running OSX10.7.4. She has a HP Photosmart 5510 and the router is a linksys, not sure of the model but fairly new. When we installed the printer it installed with no problems to her Dell desktop & Acer minicomputer & prints fine wirelessly. The software installs on her Mac (I used the latest version with the up-to-date drivers from the HP site) but will not print...gives a 'device not found' message. She can print using USB but the point of the new printer was to do it wirelessly. The Mac is connected to the router and works wirelessly for other functions. I printed a test page for router and everything passed. The printer is working wirelessly also. Something is preventing the Mac from talking to the printer. I followed the suggestions on the HP troubleshooting site but nothing works. The site did have a critical update for Lion users which I tried to download but kept getting a 'disk is full' message. This is a fairly new computer that had standard Mac software plus MS Office. It's used primarily for documents in a work environment...so no games taking up space. Not sure why this won't download but if it did maybe it would solve the problem. Otherwise, somewhere along the way Bonjour was mentioned as a possible issue. If this could be a problem, is there a resolution? Any suggestions would be greatly appreciated!!