I am in Visual Studio 2005, using 3.0.0.94 of the Janus Grid. The project is a special 'dynamics GP' type of project. If I add a standard form to the project, the grid will allow me to edit it. If I add a special form type called 'DynamicsGPForm', I get 'Can not modify the control at this time' for any type of editing task. The properties window performs as expected, though.
I've tried file permissions, I have 'everyone' set to 'full control'
Support suggested upgrading to V3.5, that fixed it.