Oh well I can now mention that the Lemminas pack you created does not load the Lemminas sprite correctly. When playing it displays an error at the beginning of the levels and revert back to default Lems sprite.
This occurs with both CE and NL installed in their own folder. Weird bc I played them Lemminas with NL some months ago and it worked correctly, did not make any change in NL since.
I can't replicate this. Lemminas sprites work fine in my test directory running CE 1.1 RC-1 and NL 12.14.
The fact that the sprites aren't working in either NL or CE suggests it's more likely to be a problem with the style rather than the engine. Here's the latest copy of the willlem_lemminas style. Try adding this to your styles directory and see if it resolves the issue.
Solved with the styles updated, thank you.