I know nothing about the FX-1 but the following was posted on another Vegas forum. Hope it helps.
Go to Control Panel/System Devices.
Right click the cam, choose Update Driver. Choose to MANUALLY install it. (Don’t search, I will install)
Now, browse to the Sound, Video, Game controllers.
Then browse to Sony. Not the Sony Electronics folder. In there, you’ll find a driver called DVHS. Double Click it. It will update. You should see the cam come in then.