Instead of moving to the same horizontal location in the previous line the caret moves to a location further to the left. If you move the caret with the mouse or arrow keys then the up arrow key works correctly, but if you are actively typing on the current line and hit up arrow the caret usually ends up in the wrong location.

Steps to reproduce:
1. Type line and a half of text in the editor.
2. Without using the mouse, hit the Up arrow key

Expected: The caret moves to the location directly above the current caret position (with the almost the same x-coordinate on the first line).
Actual: The caret moves to the location at the beginning of the first line.