I'm not saying something isnt messed up on my machine, but I am not experiencing the problem when using the DataGrid class (nor the combobox problem I've mentioned in a separate thread): in fact other things like Visibility and Readonly are also a problem when using the mm framework classes on my machine since I upgraded 1.4.1.
I've also uninstalled and reinstalled the framework without a change in the behavior.
Another thing that might be an issue is that I went from version 1.3 directly to 1.4.1 I uninstalled 1.3 and then ran the install for 1.4.1.
My next step is going to be trying to uninstall 1.4.1, install 1.4, see if that works, and then if that works, install 1.4.1. Maybe that will put me on the right path.