Why can't I redo anything in a drawing?  If I undo something on purpose -or by accident (hit the undo button while mousing to something else - hey, it happens ) - and want to redo it, I can't.  I find this to be absurd. My redo button just sits there grayed out all the time. it is useless.  I keep it there in the hopes it will occasionally turn blue .  Why would this be such a difficult option to implement into the program?