Server - WSUS 3.0 SP2 running on Windows Server 2008 R2 (I use WSUSPackagePublisher as a GUI for the WSUS API for importing/creating non MS updates/catalogs)
Workstations - Windows 7 Pro 64-bit, nothing special going on, just a bunch of domain joined machines
Update policy - Download and notify for install. We don't use deadlines, we're small enough that we can bother users who don't install updates in a timely manner, and most users use the "Install Updates and Shut Down" option when they leave for the day or for the weekend.
Issue: For the most part, when updates are downloaded to machines and ready to install, the "Install Updates and Shut Down" option becomes available to users, even for custom updates. However, I have 3 custom updates that aren't triggering that, or so it would seem, and as they're out of band with other updates that do trigger this option, I've seen relatively low installation for the past 2 weeks (roughly 5% instead of 95% after this time period). For these updates, in WSUSPackagePublisher, I've checked the option "Requires Network Connectivity" (source code out of date, but this bit may not have changed much since the last source code post).
My question is this: when making custom updates, what are things that would prevent the "Install Updates and Shut Down" option for those updates?
EDIT: Alright, it seems that by removing the "Requires network connectivity" flag made the updates available via the "Install Updates and Shut Down" method. This may end up in a few machines on my network failing to install the updates if the computer is taken offline first, I'll just have to deal with that possibility for now. Original question still stands, what defines the criteria for an update being able to be installed using the "Install Updates and Shut Down" method?