Time Machine does not back up my applications since I installed Mountain Lion

I ran a TM backup immediately before upgrading to Mountain Lion. Now I'm getting the message:
"Time Machine couldn't complete the backup to "Name of my Time Capsule". The backup disk image "My Laptop.sparsebundle" is already in use.

I've tried reselecting the Time Capsulte but still no luck. Suggestions?

fixed the problem...

found this helpful website:

http://www.mikesel.info/fixed-time-machine-error-sparsebundle-already-in-use/

BUT when I followed this fellow's directions, there was no option in Airport Utility to disconnect all users SO...

My husband reminded me that when he had a problem with Time Machine on his computer, he discovered that older versions of Airport Utility fixed problems that newer versions could not. So, he currently has an older version of Airport Utility on his Mac (5.6) as well as a more current one (Note he has not upgraded to Mountain Lion yet - he's still on Lion).

I did a Google search, found an installer for Airport Utility 5.6 but couldn't install it on Mountain Lion :-(

So, since we're on the same network, my husband used Airport Utility 5.6 on his computer and disconnected all users. I then went once again to Time Machine Preferences on my computer, disconnected from the Time Capsule, reconneted, and lo and behold, it's backing up!

Obviously, you can run Airport Utility 5.6 on Lion but not on Mountain Lion so we will be holding off on upgrading his computer to Mountain Lion. Surely there must be a way to "disconnect all users" from Airport Utility 6.1 but we can't figure it out. Anybody? Until we figure this out, he'll be sticking with Lion.

just found this... for those of you who don't have another mac running an older verson of airport utility:

http://apple.stackexchange.com/questions/45569/disconnecting-disks-from-airport- extreme