hello, i have the most peculiar problem with my printer. several months ago it started printing envelopes backwards so i started putting the envelopes in reverse to compensate. within the last month it has stopped printing. first it would only print pdf documents and now nothing. however when i do diagnostic printing it works fine. i've cleaned the heads and did test printing and it's fine. then i do a 'word' print for example and it won't print again. the paper goes through but nothing shows up on the paper. i just replaced the ink a few months ago without trouble. i guess it's something to do with software, any thoughts?