Hello,
The only render problem that I know of is with IE7. As IE8 is out since a long time you might want to update. About the fixed layout, you will have to play with .css quite a bit. operator.css has some button properties, you will have to set a fixed with for the .queuebutton as now it will use all the horizontal width you can throw at it. And then you will have to tweak the grid960 css system that was modified to use an elastic layout. You might also need to do some little changes to index.html, as you might need to modify the number of slots assigned to the right column (change grid_12 to grid_10 and grid_4 to grid_6 in the css classess assigned for extensions and queues respectively).
Best regards,