ClickOnce InPlaceHostingManager not installing prerequisites

I am having a problem automating a ClickOnce install.
I am using the InPlaceHostingManager as described in the
documentation. It works fine - absolutely no user interaction.
Unfortunately, it does not install my prerequisites (in this case
FoxPro OleDb). They just do not get installed. This causes the app to
crash the first time it tries to use the library that was a prereq.