I am using X11 and have been having the same issue. The dialog box does not even open to allow me to select a .dwg file to import. I have to hit the "esc" key to get out of the weird mode it gets in, basically locks up all of the menus etc.
Any suggestions appreciated as I never had this problem in previous versions of Chief.
ok... so I found the problem. You will need to reset the dialog boxes to factory settings.
go to Preferences->reset options->reset dialog boxes->reset dialog sizes