Switched to Lubuntu 13.04

I just installed the Lubuntu Desktop with Ubuntu 13.04. Looks so fine and it's really fast.

But I wonder why the OpenGL support is gone on my Laptop. With Ubuntu/Unity I can see games running fine with OpenGL. As soon as I log in with Lubuntu UI, games fall back to software rendering :(

I have a Laptop with Intel / nvidia 840M Dual graphics. Runs fine with Unity. But I had this problem on Peppermint OS 4, too.

Anyone knows how to solve this issue?