@ Halcyon; See, I've had many poison pools linger after battle and that did not happen to me.
It happened ALL THE TIME during my Beta game, my retail game though; never.
Did you verify your cache yet?
The only time I had effects like this was in Black Cove, where rapidly burning wood/oil did reach my Players (and far beyond) after combat ended, but that's really the only spot...
Cache verified, latest game version.
It makes sense if you stand on a pool of poison, generated during battle, that you will get affected. No problem with that mechanic. The problem is that there is a lack of time to react once the battle ends and things speed up.
I can say with 100% certainty that this issue is still active.
On the plus side, the PCs do avoid dangerous terrain while path finding. That's very nice.