losi esc ?

ive got a losi 1700 kv system in a caster buggy with an airtronics mx-3 tx and rx , my problem is with the programing between the esc and the tx, right now i have the throttle set in rev on my tx but when i let off the throttle when im running the buggy it slows down super fast like the drag brake is set at a 100%, but its not. and then when i set the throttle to frwd on my tx the buggy accelerates fine and when i let off the throttle it continues on rolling freely as it should.but then the throttle is backwards, im braking to accelerate and accelerating to brake!!! some1 help , theres got to be something i havent tried yet.