If you have a written e.g. a InfoTipHandler or ContextMenuHandler and a PropertyPageHandler and all of them are working well on your developer machine but:
on any other machine all of your handlers are working but not the PropertyPageHandler, then you maybe are missing the MS Visual C++ 2012 Runtimes (vcredist_x64/vcredist_x86) on it.
It seems that only this handler needs some DLL from it. Or maybe some other handlers I have not used till now. (Tested on a clean Windows 7 x86/x64/Vista x86).
Dave: Please provide some information on your Troubleshooting Page! It took some time to figure this out.
The second issue I found with the PropertyPageHandler is in combination with a TabControl. It doesn't matter if the TabPages are created dynamically or in static way.
When I switched (on my developer machine) between the PropertyPage and any other application (sometimes 2 times focus switch, sometimes after 10 times focus switches between the applications) the PropertyPage freezes and then the Windows Explorer crashes with
an AppHangB1. Fast workaround is of course the usage of any other controls. I have this tested this only on one machine (my developer machine), so maybe this is only a very specific issue.