In my case, all downloaded menus now show up black - even ones that originally worked ok. Therefore something has changed, probably in the registry. I opened a support ticket so maybe they can shed some light.
In any case, all work if you convert them to custom menus. Just open the black menu for modification and click the save button top left. You don't need to make any changes and you can save to the same name as the black menu.
Here is some more info about how PD8 works.
When you double-click on a dzm file, a folder is created in
C:\Documents and Settings\All Users\CyberLink\Downloaded Menus
These folders are named menu001, menu002 etc. The created folder contains all the information for that menu and you can tell them apart by opening the thumb.png file
When you save a menu in the menu editor, PD8 creates anothe folder in
C:\Documents and Settings\Arnold\My Documents\CyberLink\Custom Menus\3.0.
These folders are named menu_001, menu_002 etc. and contain the same set of information as the menu folders in
C:\...\Downloaded Menus.
When you save a menu, a new folder is always created even if you saved to the same name. That means you can have lots of menus, in menu preferences, all with the same name. The actual menu name is buried inside the menu_nnn folder in one of the .xml files. I don't like this. I think, if you use the same name, the original data should get updated and you should be warned that you will over-write existing data. I don't know why cyberlink chose to do it this way, but I am a programmer and I know it don't have to be so.
Anyway, hope this is of some help or at least interesting.
Arn