I've been having a bunch of problems with starting Civ5 from Steam, but my latest discovery is a bit unsettling.
There have been three levels of startup-issues:
A) I click Civ5 in Steam, it says "preparing" and nothing else happens.
I tried reinstalling VC2008 runtime and DX9, as well as fiddle with OS compatibility in Wine, and something of this changed the behavior to:
B.1) Now, when I click Civ, it goes into a long loop of a "preparing"-window appearing, disappearing, appearing, disappearing. It goes on for some 2-15 cycles, just as reported by other users.
B.2) About 1/3 of the times of B.1, it succeeds into getting the Civ5 window up (running in windowed mode, but fullscreen seems to do no difference) after random amount of "preparing"-windows. Here, about 1/3 times, the window remains black, or rather it's windowing-update doesn't work so it holds whatever content were drawn over it last. I "quit" the bottle and retry.
So in total, only in 1/9 attempts, the game fully starts.
Now to the unsettling part; on the few occasions of Civ actually starting, I've always seen the webcam alert-LED flicker just prior to starting Civ. What on EARTH is Civ doing with my webcam? Anyways, using that as a clue, I tried disconnecting the webcam, and voila, the B.2-problems are now greatly reduced! (5/6 on this) It also seems like the B.1 was slightly reduced, but I'm not as certain about that.
Now, why does it try to access the cam, (and why does it fail?). Anyone has any idea about this? Could it be a side-effect on other DX-initialization? If so, this might be a clue to fix the problems people have been having.