How often should you run a print Head Alignment on the average Canon printer? Because I have noticed a shift in it on some of my printers only after 3 months. The CISS printers dont seem to be affected as much as the printers with cartridges. Anyone printing and changing cartridges a lot should keep an eye on it as it should ultimately affect high quality Photo prints. I worked under the assumption that if I didnt remove the print head then an alignment would not be necessary but thats not so, does anybody have any ideas on why it should get misaligned after setting it so quickly..