UWL, Ad-hoc items not showing up

I recently configured our EP dev system to expose an R/3 workflow inbox through the Universal Worklist. This functionality appears to work as spec'd. However, locally created ad-hoc workflow items are not appearing in the UWL. While I did not test ad-hoc items before adding the R/3 system to the UWL, I have seen ad-hoc items appear in the UWL (on another EP server).

When I configured the UWL, I used a system group definition, which at this point contains a single R/3 system. It's expected that we'll have more R/3 systems added to this group in the future.

One other item: this instance of EP was constructed using the simple installer, which installs EP+KM with the expectation of communicating with R/3 system - I'm wondering if this installer set some option which as a side effect prevents us from seeing the ad-hoc workflow items.

Anyone have any suggestions?