ID:2385557
 
Resolved
The previous fix to pixel-movement collisions didn't go far enough to handle some unusual cases.
BYOND Version:512.1438
Operating System:N/A
Web Browser:N/A
Applies to:Dream Daemon
Status: Resolved (512.1439)

This issue has been resolved.
Descriptive Problem Summary:

The fix to collisions in id:2382531 was a step in the right direction but did not go far enough. Merely adding new turfs to the list for consideration and looking at the movables on them was not enough, because a movable could be considered out of contention for collision on a first pass but become a contender after a subsequent pass.
Lummox JR resolved issue with message:
The previous fix to pixel-movement collisions didn't go far enough to handle some unusual cases.
The fix for this is causing freezes.

I'll pop up a new report right fast.

http://www.byond.com/forum/?post=2385705

I also amended my test case this time with the case I think you were trying to fix in this version.

Hopefully it will be of some help to you.