There are a bunch of Erim Sever levels that are already solved! erim75 for example. What's up with that?? *confused*
Ah, found the answer. From Erim's website:
"At July 01, 2004 This style born & share from me!
Based on an idea suggested from me and was the first author of the "Start-With-End-Position" Levels (maybe because of a program bug). (at 01/July/2004 I sent an email to yahoo sokoban group for share my idea & these new levels)
For Sokoban & SokoMindPlus & Hexoban & HexobanPlus & Multiban & MultibanPlus & "All Sokoban Style Games" where all boxes are already on goal tiles (level as solved)! After the first move (normally a forced push), the player has to solve it again which may take many more moves than the one move at the beginning !
Still lots of games gives a bug when you play first move/push and made 1 undo after that. "