Comment 4 for bug 776560

By process of elimination, I was able to pinpoint to this ie specific style in karl_ie.css:
img {
    -ms-interpolation-mode:bicubic;
}

If I add an additional style to have it default back to the nearest-neighbor interpolation mode for the login gradient, then it seems to work properly.

I tracked down where the change came from through the commits: (6105 6068 5938 5917)
Commit message for 5917:
rounded styles for IE feeds (LP #612389)

I think it should be fine if I set it to nearest neighbor just for the login gradient, to be safe and not affect anything else.

r6788