Jagged fill

[Mladen]

I tried the search button, but didn't quite find an answer to my question. I'm sure it's something pretty simple, however I can't seem to find the answer. Check out the pic (and .xar file) this is a rectangle with a simple linear fill from very light grey to white. Whatever I do, however it it stays jagged. Zoom it further and it really shows. What am I doing wrong? Please guys, help me here.linear.xar