Try to print out this color test page and see how your colors look. http://inkjetprinterhelp.us/Color0.gif
This page will help you figure out if one of your colors is acting up. Then I would take the cartridges out, take the print head out and clean it up (with napkin and rubbing alcohol; be sure to not touch the bottom of the printhead or else you will damage it!) to make sure that the colors aren't mixing with one another. Since the cartridge leaks a little bit, this might be the problem. When you install the cartridges back in, flip the cartridge upside down fast so the colors won't mix. Another customer stated that you can use Scotch tape to tape up the air vent holes to slow down the leakage and then take the tape off after the cartridges are seated into place.
Call us if you still have any questions or concerns and we'll be more than happy to help you out!
9:30am-5:00pm (PST) M-F