Printer no longer prints Custom sized paper or envelopes

I have had the Laser Jet Pro CM1415fnw colorMFP since Feb, 2011. When I first got the printer I had no problems with printing special sized paper, but now I do.  I can no longer print 8"x8" card stock (which I used to do often for craft projects!) without having similr issues as I have listed below.
I am currently trying to print 3-5/8" x 6-1/2" envelopes. I have the "Page Setup" set in Word, I checked the "Printer Properties" and the sizes are correct. On the printer settings I have "Tray 1", "Envelope", "Custom". After each envelope is printed, the printer goes through a "cleaning", then it alerts "Unexpected paper size in tray 1. Load Env #10. Press OK to contiune." I press OK. Then it alerts "Load tray 1, Envelope, Env #10. Or press OK to use available media"  (a #10 envelope is not the size I am trying to print, nor the size in Word or Printer Properties).  With all of these steps, it has taken me 2 hours to print 35 envelopes, and I need 100 of them! This is insane, please help!