I do not recommend disabling UAC entirely, since it allows people to edit their GTA files however they want and join your server.
A better way would be to use the Anticheat.uac file and place any files you want to be checksum'd in there.
The functionality is explained
Here.
In the future we may disable checksumming the weapon, handling and surface datafiles if the server has its own copy since the local copy is ignored then and it makes no sense verifying a file that wont be used.
