Exp. Player V11.14.19:C474AF8
The update of for some reason messes up the position of the pre-placed lemmings. See below for an example: in Breezy 3, all the lemmings should be blockers in the old version, but after the conversion, the pre-placed lemmings are walking. I didn't even use any walkers on them.
Also, in the editor, it is shown that the pre-placed lemmings are buried within the terrain.
Will look into the positioning issue during conversion. Regarding the positioning in the editor, it'd appear the editor is placing the topleft corner of the lemming graphic at the preplaced lemming's position, rather than placing the lemming's foot at that position; this is something that Nepster would have to fix.
Thanks for the bug report. I fixed the editor bug, so that the preplaced lemmings will be placed correctly in the editor.
This of course depends on what exactly is the problem when converting the levels. More precisely the statement above assumes that the current level converted places all preplaced lemmings exactly one pixel too high.