You are holding the bolt head up inside the bracket with a wrench while using a socket on the nylock nut right? <img border="0" title="" alt="[Wink]" src="images/icons/wink.gif" /> Otherwise I dont know why it wont back out <img border="0" title="" alt="[Frown]" src="images/icons/frown.gif" /> ...looks like you will have to cut the nut off. Dremmel tool with cutoff wheel should work fine.

Good Luck.