c# - Hosting a WPF usercontrol in a Windows form -

i have wpf keyboard control hosted in windows form control. works fin on computers, not on all.

for reason or another, on computers when open win form wpf keyboard wpf control blank. empty square instead of keyboard.

all of parts of project in .net 3.0 , built in c# 3.

anybody have ideas?

update

i unfortunately don't have access computer self via person on other end of phone.

i've tried setting computer without .net 3.0. gives me error message

tried .net 3.0 without service pack also, doesn't recreate problem.

did ensure have right version of .net installed on computers in not working ?