Disk utility won't delete partition.
I installed Ubuntu on my Macbook but it didn't really work for me so I deleted it. I used Disk Utility to delete the Ubuntu partition, but when I want to delete a Linux-swap partition I made while installing Ubuntu nothing happens. I press the minus button and it will delete it. But after deleting it just stays there, and I can't change the partition in any way. How can I delete the partition?
MacBook Pro, Mac OS X (10.7.4)