I've got this Canon all-in-one that started showing this issue all of a sudden; I use original cartridges which I refill by myself; this one is a CL-38, 9 months old, which i've refilled two or tree times per colour. If I print the noozle-check page I get only the black,cyan and yellow panels printed correcty; the magenta one is totally blank! I tried cleaning the noozles, both light and deep cleaning process, but nothing changed. I created then a 100% magenta coloured page for the printer to print, thinking it might clear that noozle somehow, but it gives me back a blank sheet: not even a single magenta dot gets printed! The cartridge is full and clean and as I gently rub it on a soft tissue it leaves a cyan, a magenta and a yellow stripe, so I guess it is not a clogged-head issue. I'm running out of ideas...any tips? Thank you in advantage!