At a customers site with OpsMgr SP1 in place there were multiple hotfixes applied on the Management Servers. However, not all of these hotfixes weren’t applied to the newly pushed OpsMgr Agents, even though the Agent staging folder (~\Program Files\System Center Operations Manager 2007\AgentManagement\<architecture>) was correct: permissions OK and all files (msi, msp’s and so on) were present.
Strangest thing was that only hotfix KB954903 got installed, but the others (KB957511 & KB958490) weren’t. No errors what so ever in the event logs.
So I checked one of mine test environments to see if there were any differences. And yes, there was. The problematic staging folder had an extra msp file for KB956240.
This is strange since this hotfix isn’t meant for Agents but for Management Servers only. In combination with this hotfix a sql-query has to be run on the OpsMgr database as well. However, none of it is OpsMgr Agent related.
So I removed those files (Q956240-x64.msp and Q956240-x86.msp) from the Agent staging folder and pushed an Agent to another server. Yes! All hotfixes got installed. Even double checked it by looking at the file versions.