If it's not giving you an error complaining about the plugin at startup, then those symptoms suggest it's in the wrong folder, and just not being found. I don't have that version of MAX, so I don't know if they re-arranged things so that the unzip would put it in the wrong place. Do you have more than one plugin folder now?
The usual failure mode when a plugin is not compatible is that it will either fail to register at startup, with an error message popped up at that stage, or it will crash when you try to use it.
Ah, I think I see what went wrong. It tried installing it into Autodesk > "3ds Max 2009)", which it had to create itself, instead of "3ds Max 2010"
The plugin folders and everything look the same in each, so I'm going to try moving it over manually.
-Edit- Still has exactly the same issue as before.