See this. The icon (this is the size) is being cut off when there is opacity blocking the root (being the left-most tile), but not the whole icon.
Numbered Steps to Reproduce Problem:
Make a large icon.
Put it on the map, and make it so you can obscure just the bottom-left-most corner of it.
Load the map, and see it there.
Walk into the opacity, and see the whole icon vanish.
Code Snippet (if applicable) to Reproduce Problem:
For the whole icon to be visible, no matter what.
The icon is chopped off.
Does the problem occur:
Every time? Or how often? Every time.
In other games? I imagine so.
In other user accounts? I imagine so.
On other computers? I imagine so.
When does the problem NOT occur?
When not using opacity.
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.)
Chop up the icon when it is created and spawn some dummy objects.. although that can be rather intensive.