did you buy it at walmart? i heard they limit all their guns to semi auto because they dont want to get a bad image as being providers of "automatic weapons." ive seen somewhere how to put some kind of breaker on the board that allows you to use full auto but i forgot where i saw it at. i have an e rex pro and mine has all the functions on it, you might have yours confused with the e rex elite, and i know theres another e rex thats so crappy i cant remember the name. make sure you have the right one
edit: in ym manual it says there are indeed three types of e rex's, the DME2, DME3, and DME4 the DME2 is just called "e rex" the next one is e rex elite and the dme4 is the e rex pro. please dont tell me you have the DME2...