I reported a problem where LH was still running for an extended period after exiting the game, forcing me to kill it with task manager, and a couple of other people said they'd seen the same thing.  Could that be what you're seeing, rather than a Steam problem?

No the game has closed completely, I'm sure of it. I checked under processes and it's not there. I can't close Steam the normal way either, it fails to close to LH, probably because it can't find it running, which is why I have to force close the steam process. This only started happening after the last steam patch, and it's 100% of the time. I can close LH normally through the menu, I can force close it after it freezes, or it can crash, in all case Steam still thinks it's running.

Could it be that it's saving to the cloud?

Would this be why the game I played after playing LH lagged like hell until Irestarted my computer?  Could very well be.

::Fidgeting impatiently::  Is it here yet?  Is it here yet?  Is it here yet?

Can we at least get it by tomorrow?  I don't have internet at home so I need to download it while at work. 

Patch didn't work. Just opening LH and quitting right away from the menu (never even starting a game) then trying to open it again several minutes later I get:

"Steam - Error

Failed to start game (app already running)."

Opening taskmanager and checking processes (Vista) I can again confirm the game is not running.

I tried turning syncing back on to see if maybe that being off somehow caused it, but the game doesn't sync because steam doesn't think it's closing.

Same here. Closed and restarted several times, no probs. I'm running Win 7, so could it be some issue with Vista?

Vista users? Buehler?

If it makes a difference I have Vista 64bit.

I've tried everything short of reinstalling both Steam and LH just to see if it was one of my settings or something. Tried offline, tried without steam in-game community, tried turning mods off in LH, verified both installs, checked steam for updates, and tried launching LH from 3 different locations (desktop, steam taskbar icon, and from within steam). It happens every single time since yesterday, and it never happened at all before (and I was restarting LH a lot before because of the reloading from within game issues).

It also does something weird when I close LH. I get the normal windows pointer with the little circle next to it in one second bursts off and on for like 10 seconds, but my PC isn't slow at all or seeming like it's doing anything.

Also been playing the steam version of Defiance without any issues.

It would probably-definitely be gameoverlayui causing the problem them. It doesn't always close cleanly, specially if the game it was open for crashes (L4D2/TF2 some times for me). If it happens to you a lot, turn it off in the settings and see how you go.

Most of the things you tried probably wouldn't have an effect on your problem. It could be other programs you have running too.

I was mistaken, this doesn't happen with any other game on Steam. I tried about a dozen of them. Also updated Steam to the latest beta and it had no effect. Starting to get a little annoying. >.<

Here's my debug.err, if it helps.

http://sites.google.com/site/insanati/debug.err