I'm not completetely sure, I'll have to check it later, but I think you missed some blind mudokons between steps 5 an 6.
After leading the three blind mudokons through the trapdoors, don't save them yet. Instead, make them follow you to the left, where you will find four wheels to be operated.
Use the blind muds to operate the wheels. A platform will descend from the ceiling and you, with your fellows will have access to another screen with a few blind mudokons. Save them all and get the hell outta there.
