Korg Digital Legacy Collection GUIs don't display properly

Happy New Year, all!
 
I don't know if anyone else has had this problem, but a search on this forum revealed nothing, so here goes....
 
The latest version of Korg DLC has GUI problems in moderately large SONAR projects. If I load Polysix, M1 or the others in a project that already has many instruments (but isn't straining my system), the GUI is just a black box. However, the GUI is fine if the synth is loaded into a new project. In either case, the synth will make sounds, but obviously when it's all black, I can't change any settings or even call up presets.
 
I've un-/re-installed the Korg synths and the Intel HD 4600 video driver in the Windows 7 (64-bit) system. Changing screen resolution or color depth doesn't help, which leads me to believe this isn't necessarily a video driver issue.
 
Again, it only happens in SONAR tracks that already have quite a few (8-10) instruments. In a new, empty project, the GUIs work properly.
 
Anyone have any ideas on what this could be?
 
Thanks.
 
Steve