Hi Juan,
When you say reds, do you also find that pinks and blues how any
weakness of color? I'm asking because I believe the i560 uses CMYK ink
color set up, so the ink colors would be cyan (blue green) magenta
(pink) yellow and black. If the magenta head is creating problems it
would alter the reds (making them more orange) the blues, making them
more greenish and the pinks, making them weaker as well.
Has this problem just started recently? Did you change anything else,
like the printer driver, the program you use for image processing, etc?
Art