omg. sry for repost but i found my post here on forums few years ago.
and this bug still there
http://hutonggames.com/playmakerforum/index.php?topic=9586.0steps for repeat:
1. create object (cube/sphere/capsule)
2. make materials size 2
3. create 2 materails with different names and place them on created object
4. create fsm on sphere (or where you want)
5. create state in fsm
6. go to action browser, find and place get material
7. set shared material
8. set index 1
9. hit play and watch value status in variables section
and pls, fix this small problem, because i cant rewrite code everytime i upgrade playmaker
tool is great, its complicated and have nice upgrades, but 2 years and still...