We just fixed a printer for a lady who’s problem I have never heard of. When she tried to align the cartridges (done automaticly with her printer), it would spit out the blank paper and say paper mismatch.
After some research, I found two possible solutions.
1. Clean the contacts and the paper sensor as HP describes on their website (look the HP PSC 2175 and you will be able to see the pictures. Please note, this did not work for me.
2. When the cartridge alignment comes up, press “Setup” and “Options” together to cancel it. If the paper mismatch appears, hit the “Cancel” button.
This is more of a band-aid than anything else. But it does work.