Some maps occupying map01 that have a map header will cause level select to start at GFZ2; this bug has been obvserved in previous 2.0 versions, but as of 2.0.6, moving back to map01 in the level select dialogue will cause the game to crash without an error message.
Can be observed with this map.
EIP=0049624a
Can be observed with this map.
EIP=0049624a