Thanks for the reply. I will give it a try. We also have a Levono Idea Pad P500 in the house, it also has no working brightness control. Prior to the upgrade I think it was stuck on 50%, and looks like its now at 100%. I gave feed back to Microsoft, but would be very surprised if our issues get fixed by an upgrade/patch.
Very surprised?! It is definitely a serious bug in the April update, so not fixing this issue would be a scandal in my opinion.