I had the same problem as described in the OP, but with WA 2.2.8 installed.

Here's how I fixed it:
First I moved the userPresets.package from "My Documents\Electronic Arts\The Sims 3\" to a safe place (desktop).
The game then started correctly even with AM installed.
I quit the game right away and put the userPresets.package back.
I started the game again and now it worked with AM installed and all my saved patterns still there.

Also, before each restart of the game I deleted all the *cache.package files.

I found out that if you turn off Shaders you'll get the shiny looking toilets.

That also explains why Flickan had the shiny effect a couple of computers ago when the graphics card wasn't able to use Shaders yet.
All the newer graphics cards can use Shaders which should make objects look more realistic, but in this case makes the Maxis EA toilets actually look less realistic.
With Shaders turned off the game looks lighter overall.

"boolprop useShaders false" turns Shaders off.

But as the picture from Solander's shiny toilet shows, Maxis EA could have made their toilets shiny as well with Shaders if they had wanted to.