Hi Michael,
Good timing. :) We just updated some code to better support the disabling of tabs a few minutes ago, which will appear in the next maintenance release.
Right now you can disable a Tab by setting its IsEnabled property to false. You may have to cast the reference to Tab to since IRibbonControl only currently defines a getter (via IInputElement) but Tab defines a getter and setter. Once IsEnabled is false, the Tab can no longer be clicked on to select it.
The problems in the current build are that the Tab text doesn't render in the disabled color in this state. Also mouse wheel tab selection will still select the tab. Both of these items have been updated for the next maintenance release.
Additionally we will add an IsEnabled setter to IRibbonControl so that the casting is no longer needed.
[Modified at 06/13/2007 08:09 AM]
