Not sure about the scrolling, my guess is the World.ini editor somehow intercepts the messages sent to the level editor.
I honestly don't know about the transparency thing. I mean, I never save any kind of image.
But well, custom objects don't support magenta transparency anyway, I thought?
A crash is the consequence of an illegal operation, e.g. writing to a protected chunk of data in the RAM.
A freeze is basically just an "infinite" loop that stops the main program loop from being executed (Well, yeah, almost all programs use loops).
Usually they occur because the programmer forgot to set a limit or an exit for the loop.
Thanks.