Descriptive Problem Summary:
The DM Icon Editor seems to glitch out when switching between icons in draw mode.

Numbered Steps to Reproduce Problem:
Open two icons with a resolution of around 200x200 or higher.
Open an icon_state to enter the drawing mode for both icons.
Switch tabs back and forth between the two open icons.

Expected Results:
The new icon should be displayed with the drawing tools around it.

Actual Results:
The screen flickers several times before finally showing the correct display.

Sometimes it appears to display icon A, then B again, then displays icon A and stops.

When does the problem NOT occur?
It seems to happen with smaller icons as well, but since the icons are small the screen is able to draw much faster, making it harder to notice.