It hasn't happened every time for me either this is the problem, and it only seemed to happen about 20 seconds after I had been returned to the puzzle edit screen.
Also, during editing, I've noticed another one (you love me really don't ya? :) )
Once, when saving the level, I heard the sliding block noise and another copy of maxter appeared and some new blocks.
When I reloaded the level, some of the blocks were non-editable (restarting the program solves this issue).
Also, during editing, I've noticed another one (you love me really don't ya? :) )
Once, when saving the level, I heard the sliding block noise and another copy of maxter appeared and some new blocks.
When I reloaded the level, some of the blocks were non-editable (restarting the program solves this issue).