I encountered a similar but not the same problem. I have two lion computers at home with ARD Admin at work, one at each of our two locations, and one at home that can connect to our firewall box and work within the network. All Lion 10.7.4. I updated the one at home first to 3.5.2 and it had no problems controlling the other two.
Then at work I updated the one that is "remote" and not directly in the office (updated by controlling in ARD as a matter of fact). After updating the Admin to 3.5.2, I could not control the computer from one that was not updated. I could "copy to", but not observe or control.
I got home and same thing - could not control/observe the computer that was updated to Admin 3.5.2, could observe/control the one still at Admin 3.5.1.
I have seen others with problems in this genre resolve by kickstarting the computer (or turning management off and on if physically at it), so tried that - ssh'd in and used the kickstart command. Amazingly, it worked.
I used Remote Desktop Help for the kickstart command syntax. was following for user "admin"
sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/k ickstart -activate -configure -access -on -users admin -privs -all -restart -agent -menu
My problem was just with ARD admin computers. I have couple other Lions without ARD admin and they were never a problem after the update to 3.5.2. Note: everything has 3.5.3 for the client.