Descriptive Problem Summary:
Changing the transform variable of an atom, specifically with the Turn() function, results in the atom appearing on the wrong tile. Does NOT occur on the vast majority of machines, only those with minimal or outdated graphics hardware, in addition to virtual machines. May be DirectX related.

Numbered Steps to Reproduce Problem:
1. Boot up a Windows 7 VM.
2. Make a simple test project.
3. Set your mob's transform variable to a matrix turned at 90 degrees.
4. The mob will appear one tile above the tile its actually on.
https://gyazo.com/dcb51b95f90b9ddfc47c6c812a014b87

Does the problem occur:
Every time? Or how often?
Every time on applicable machines.

In other games?
Yes.

In other user accounts?
Yes.

On other computers?
Yes.

When does the problem NOT occur?
On the vast majority of machines (as well as Wine)

Did the problem NOT occur in any earlier versions? If so, what was the last version that worked? (Visit http://www.byond.com/download/build to download old versions for testing.)
The problem does not occur on 512 builds below 1455.

Workarounds:
Use 512.1454 or earlier.