Clients not installing patches

I have a group of agents ( not sure how widespread) that are not kicking off the patch cycles.  If I look at the agent on the computer it lists patches as ready to install on the software updates tab.  I can manually kick off the patches and they do install and ask for a reboot.  But they are obviously not kicking off when they are supposed to.  They also do not have any software update events if I look at them in the resource manager under events.  Other agents seem to working fine.  Want I need to do is find a fix and a way to identify these computers.  I have not opened a case with symantec yet.