For example after Hiding elements I click Hide again and get normal "Select objects to show or done to show all" message but no Done button to click :?

I restarted my computer, reinstalled my Graphic card driver even reinstalled MOI. Gone, no more Done and Cancel Buttons???
What is going on? What can cause that strange behaviour.

I'm running MOI 1.0 but I get the same behaviour with MOI beta 2.0
Gaston
p.s. Yesterday I installed Google Chrome and IE8 Could that have something to do with it?