Not sure if this has been mentioned in the past 49 pages, but I too was having the same problem and two things really helped 1) Even though I thought I uninstalled KPS from my Windows 7 machine, the Kerbal Space Program folder was still left in the "~\Steam\Steamapps\Common" folder. Delete that first, then download the entire update from Steam. If you do that, you will get a clean install. 2) I normally place fins on my rockets so they have control in the atmostphere. No matter how many reaction wheels I put on, I would completely lose control. Out of a whim, i removed the fins, and the rocket came under complete control, just like we saw in the previews. Give it a try. Hope it works for you, as it did for me.
