Tip: Switch palace switches normally disappear if you replay the level. However, if you insert them as direct Map16 and use the hex-edit at $00EEB2 in the ROM map, you can replay the level without a problem.
The sprite<->tide interaction code is messed up in the original SMW. While the original levels never seem to run into this problem, you can find it if you e.g. place some floating platforms (5B through 5E) in level 102 (they will randomly start to levitate). This patch fixes this bug.