The way I use the ribbon bar is simulating a tab ribbon with all of the control buttons on the page concentrated in the ribbon bar. When you switch the tab, the entire UI appear to switch to a different "section" of the application. Hiding and showing of groups is done to accomodate the control needs of the sub-sections. 

I solved the problem for my need by simply forcing the width of the RibbinBar to 2500px - this covers almost all screen sizes out there today and fools the code to stop reducing the size of the buttons when taking itno account the hidden groups too

It works for my clients and the work-around I mentioned above appears to be working fine in all browsers. Also by setting the solid width that extends way beyond the width of the widest browser is bringing the benefit of fooling the ribbon bar not to recalculate itself on broser resizing, which in turn does not activate the hidden groups, which prevents the flicker wich is inevitable while my code is trying to hide the groups that should be hidden. It is true that I lost the additional buttons at the right top of the ribbon bar, but all of those can be simulated with javascript commands so an overlay div with "fake" buttons at the top-right corner of the page does the trick.

That being said, I would preffer to use native functionalities, which is always a better approach in the long run, so this proposed feature would definitely be something I look forward to.

So, thank you, guys and gals, for listening to our requests...  :)

Sincerely,
Peter From LA