Button in cell not responding on iPad
===

I have a strange problem with buttons placed in table view cells on the iPad.

Here are two screenshots for better understanding (the button is on the right side and has a white background color):

[iPhone](http://imageshack.us/photo/my-images/822/bildschirmfoto20120724u.png)

[iPad](http://imageshack.us/photo/my-images/856/bildschirmfoto20120724u.png)

No problem with the iPhone, but on the iPad this button is not responding. 
The positioning seems to be right, as it is drawn correctly.

To ensure the button is on top I have this:

[self.contentView bringSubviewToFront: rightButton];

Any ideas on this?