Black corners on UITableView Group Style

I have a problem where my UITableView (group style) has a black "tip" above it's rounded corner.

I'm setting up the background of the tableview like so:

[meetingTableView setBackgroundColor:[[UIColor alloc] initWithPatternImage:[[UIImage alloc] initWithContentsOfFile:@"background.png"]]];

And my table view ends up looking like this:

black pointy edge on rounded corner http://papernapkin.org/pastebin/resource/images/imageEntryId/6487

Any ideas how I can get rid of those black points?

I have got the same problem. When I set clear color by xib, I have the back corner The solution is to set it by code !

(The same problem with interface builder exist for webviews)