'Find My Mac' says that it is already in use, how to fully remove previous configuration? I posted a question earlier about using Find My Mac while my computer was sleeping, and after doing some research I noticed that I had 'Wake for network access' already enabled. So when I went to check iCloud again, I noticed it saying this (Find My Mac already in use): 



If I check the box, I then get this alert message: 



The only thing I can think of, is that I may have signed in with another iCloud account on this computer (I have an old iTunes account, plus a mobile me converted account that I actually use). 

bmike mentioned he had see registration issues with Lion updates, and not sure if this was related to something similar, or to possibly linking this computer with another iCloud account originally. I want that original one gone, and only my new one to go. 

My question is: Is there any where else I should look for remnants of this 'other' iCloud account, to not cause other issues? I know this was working at some point, even recently, so it confuses me on what happened here. 

Update: So I went ahead and checked this, clicked Continue below, and it appears to work fine. I would still like to find what ID or anything else that would cause this though to help understand it if it happens again.
I had this happen to me a couple of months ago.  I was perplexed, as you were, about what could be causing it.  I figured out the following, but as there's no information for this online it could be incorrect:


Find My Mac is tied to the serial number of your Mac
Find My Mac was partially enabled before iCloud was released
Since it was partially enabled, a previous MobileMe account could cause conflicts.


Again, I have no definitive proof for this.  But I got this notice on a fresh install of the operating system, only after upgrading my MobileMe account to an iCloud account.

So if I were you I wouldn't worry about it.  Most likely it's just a MobileMe bug that never got quite resolved.