Mh. One interesting thing I noticed. ZCM 10.3.3 on SLES 11 SP1, HP Compaq dc7100 (maybe other HP devices, too), Windows XP SP3, latest patches. Sometimes I see that computer is hung on shutdown (sometimes on startup), only I see background wo cad, mouse does work, ctrl-alt-del not, does not ping, only power switch does help out. I renew BIOS, video and lan drivers and tried after startup almost at once (when computer start to respond to ping and cad appear) restart ... hung again and seems to constantly. Then I stopped at once after computer startup ZenWorks Agent service and ... restart was just fine. When I wait till ZenWorks Agent service is done (it takes some 10 minutes to happen, I see as I have some bundles to run every time at bootup) and then restart ... seems to be also ok. No errors in logs, neither in events.
Sure, could be some other service etc. which causes this kind of hanging, though.