I still have my old i23 install, and put i24 in a new location. if I fire up i23, I have all my keybinds. If I fire up i24, I have to do everything by hand in the chat window.
I'm guessing it's based off the Installation Directory setting in your registry, under HKEY_CURRENT_USER\Software\Cryptic\CoH
Don't know for sure, though.