I was looking at a file in a ST3 window that was read-only. I checked it out from perforce, and then proceeded to modify the file in ST3. Trying to save the file causes an error dialog to pop up - "Sublime Text
Unable to save
path/filename
"

I reverted it in Perforce, closed and restarted ST3. I can still edit the file for some reason, even though its read-only. I can try to save it, but the dialog still pops up. Doing all of these steps using ST2 works as expected.