I've switched to Holiday Ornaments Red, one of the Expressive Winter layouts, for Christmas, but there appears to be a problem the the way the header displays in Firefox (and also Flock, which uses the same rendering engine). There's an extra red line at the bottom of the header image, as if the header, which doesn't have a straight edge, has a red box round it. It doesn't show up in Opera or IE, though.
So I was wondering if there was anything I could do to get rid of it, as it's rather irritating. I have a paid account and am quite happy adding developer area customisations, if that's what's needed.