Autorun/Autoplay not working on home PC

At work, when I plug my flash drive in or connect my cell phone, Windows comes up and asks what I want to do. I can start PA (on the flash drive), open the folder, do nothing, or use various helper applications. Works great, this is how it's supposed to work.

At home, when I plug them in - nothing happens. They don't have autorun menus. They don't even show up in My Computer. If I don't know the drive letter, I can't access them. (My flash drive is L, my phone is H.)

I installed TweakUI and both drive letters are checked off in the list of drives to show in My Computer.

When I right-click in the root of the drive and go to Properties and go to the Autoplay tab, they're both set to ask what to do, not the "Do nothing" option.

(Just so we're clear, I'm not talking about trying to get the flash drive to autoexec the PA menu at insertion - someone suggested that and the debate got a little heated. That isn't what I'm talking about at all. I wouldn't mind it but I understand why it doesn't and shouldn't.)