I'm also experiencing 1px at the top of the screen when using a custom
header background.
FYI the header background has some weirdness across different tabs:
When reading a blog entry the header image dissapears leaving just the
background color.
The "More Tab" doesn't show the custom header background, although I'm
thinking this is an Apple limitation not a bug.
The app crashes on load when a custom header background is set on a
"BCResourceWebViewController" tab as well.
Lloyd Hannesson