Can DX not initialize on a hidden window?
Actually, from memory I think it's MacOS that has problems with that - gl context is not valid until window is visible or something.
Have you tried a 0,0 width,height graphics?
In retrospect, I messed up with the 'core' graphics module - it's redundant and shouldn't be there. Would love to clean it up but have 1001 other things to do first!