My machine is a SC 545. I was running a banner job when I noticed that yellow wasn't printing as it had previously---not enough magenta. When I checked the ink levels, I discovered that Light magenta was out---although there was no warning. I replaced the light magenta, and ran a cleaning. After three test prints, the light magenta was coming back---after the fourth test print, a black line appeared across the regular magenta, and stayed there, while the light magenta tested less and less. Does anyone have an idea of what's up? Any help or advice would be appreciated...