we see a problem with the new zenagent 11.2.1 and zac.exe command.
With only user rights the zac.exe command don´t exit (zac --help in a dos-box show the help and don´t come back to the prompt).
(win7 / sp1 / fully patched / UAC Off)
No problems with zenagent 11.1!
With UAC ON the administrator account have the same problem.