Please ensure that %windir%\system32\evr.dll and milcore.dll have the same date/time stamp (well, at least the dates should be the same). If not, please uninstall WPF, manually delete evr.dll and milcore.dll if they are left behind, and reinstall WPF.
I will try this tomorrow. Is there a reason this might happen? I was hoping to deploy this app to a lot (as in hundreds) of machines at some point and if I can find out why (previous beta or something) I can be a little more confident on releasing.