I have also began experiencing this problem in the last month.
Attempting to install any package using ARD will indicate that it requires a restart of the client. It did not work this way a few weeks ago. I'm not sure why it has suddenly started working this way.
I run ARD from my iMac with 10.7.5. Clients have 10.7.5. ARD Admin 3.6.1, Clients 3.6.2.
I have tried rebooting my iMac, and pulling the packages from different sources, still the same problem.
If anyone has a solution I would appreciate knowing what it is.
I just wanted to provide some additional information.
This problem only occurs when the source package is located in a folder on a system over the network. The other admin here performed the same test from his system and is getting the same results. That is, when attempting to install a package which is located in a network folder then the package will indicate that the client system requires a restart.
If I copy the package from the network folder to my iMac it will want to install correctly and will not require a restart of the client.
A work around is for each admin to have and maintain a duplicate set of packages. Typically we have used a network folder for all of the Apple install packages. This problem started occuring in the last month or so, no idea why at this point.