Weird black corners at edge of Grouped UITableView

I have an UITableView in my application, which is in an UIView that has it's background colour to the Scroll View Texture thing. This is all in an UIViewController. It works all nicely and stuff, but I get these fugly black corners around my table view edges:

The Background colour of the table view is set to the clear colour, and those squares even appear in Interface Builder. Any ideas on how to eradicate these evil UI blemishes? They make my UI look like something that was thrown together in 3 minutes, even when I spent more than a week design开发者_如何学运维ing my entire UI. It makes me want to punch UITableView in the face, too.

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Quite strangely, setting the background to clear in code seemed to solve it for me. It is a really weird issue, and I submitteda bug report to Apple about this, although their bug reporter needs it's own bug reporter.

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Also make sure the background color is not just clear color, but that opaque is NO.