ahhhh another beltway beater

Sorry you're stuck in DC too
Did you try the Reset Forms button on the autocomplete form?
According to MS no a website doesn't actually see the contents of that drop down list as it is stored locally. However, I wouldn't be suprised if there is a vulnerability to allow it
I believe the information is stored in a .dat file somewhere in your profile.
Don't think it would do any good to do a search for it as MS typically doesn't use plain text to store stuff.