extract it to the desktop, then open a terminal and type what follows:
cd desktop sudo -s (Type your admin password) chmod -R 755 beamsync chown -R root:wheel beamsync ./beamsync -d exit exit
Now Re-launch Finder or, if you prefer, reboot your system.
Now BeamSync is permanently deactivated.
If, for any reasons, you want to re-activate beamsync use the same program but with different options...
./beamsync -d ---> Deactivates beamsync
./beamsync -a ---> Automatically activates beamsync
./beamsync -f ---> Forces beamsync to be activated
That's all guys.
P.S.: if it doesn't work, try first enabling Quark 2D Extreme, as described in another topic here.