Transparent background in grouped UITableView - iPhone

I had this issue and found that there was no difference between using:

[[UIColor alloc] initWithWhite:1 alpha:0.0];

and using:

[UIColor clearColor];

I tried both of these and still had the little black corners on my table view.

I also tried setting the backgroundView to nil as suggested, but this didn't work either.

I solved this by setting the backgrounds of the individual cells to transparent in the cellForRowAtIndexPath method:

cell.backgroundColor =  [UIColor clearColor];

Of course, this has the side effect that your cells themselves are transparent, which isn't ideal for everyone, but it ok for me in this case.