Hi Latest official firmware is 3.7.3.3 here ftp://ftp.draytek.com/Vigor2860/v3.7.3.3/
Not sure if will help but worth have the latest (if you do use *RST* file)
Router Firmware 3.7.3 did not work very well, I got slow connections and had DNS issues. Upgrading to 3.7.3.3 and resetting the router worked perfectly.