ever since I installed last patch tuesday's updates my S2 has a major bug when the TypeCover is attached. Basically the title says it all. The thing won't go into connected standby anymore. Detaching the Cover "fixes" the problem but that is no satisfying solution, obviously. The problem is reproducable and not a "once in a while" thing...it happens all the time and results in a battery drain even when not using the S2 actively.
I'm not alone with this as can be seen over at WPCentral's Forum, where we are discussing the problem: http://forums.wpcentral.com/microsoft-surface-2/269245-fix-wake-issue-not-working.html#post2405630