I have an HP C4480 All-In-One printer. Scanning works, but when I try to print, it gives me a "Paper Size Mismatch" error. I have chosen different paper sizes (A4, etc), tried different OSes, and tried different sized paper. Sometimes the printer works, but rarely. This was not always the case. The printer is only about 6 months old with my macbook, and began having this problem 2 months ago. The ink is brand new, and there's paper. The problem might be that the paper size sensor is dirty or broken, and I read somewhere that I can physicall disable/remove this.. or maybe in the software. Please help!