I've had weird experiences with invisible platforms, too, but they usually kill me. Like, once I was playing "Lost Levels" and I hit a Koopa Paratroopa and it fell to the bottom of the screen, but kept strutting from side to side, so I figured there was solid ground there. I was jumping between pipes and the next one had a Piranha Plant in it so rather than risk getting shrunk, I dropped down to the platform the Koopa was walking on. It turned out it was a glitch, and the Koopa continued walking on thin air while I plummeted beyond the invisible platform to my death. A lot of the time glitches kill me, especially in the original "Super Mario Bros."