Delete the Documents\Electronic Arts\The Sims 3\Mods folder and start try again from step 1. Everything okay? Do your folders look as they should in step 4 and step 5, with all the right files/folders in place? Icon and exactly what it says for 'type' are irrelevant as far as working in the game is concerned - what matters is that it ends with. It's okay if your icon looks like a Sims 2 package icon, a monkey, a white sheet of paper, or anything else, and the type may say 'PACKAGE' or something else.

Note: The picture shows them with a little green plumbbob icon, and 'Sims3 Package' under Type. Inside the Documents\Electronic Arts\The Sims 3\Packages folder Check Packages Folder: Your Documents\Electronic Arts\The Sims 3\Mods\Packages folder should have two files inside it: NoBuildSparkles.package, and nointro.package