Mine works fine... I don't replace bike parts until they break. The one in the picture above has outlived six frames. The bike it's on is a total mishmosh Frankenstein of old parts.
in the setup click link above.... look under sis adjustment there is a photo showing the removal of a "pro set alignment block" maybe that is the block stopping it from moving all the way... It doesn't say to put it back in.
I have the same lx deralier. I checked the adjustment on my shifter, if you screw the plastic fitting all the way in where the cable goes into the shifter, it won't let the shifter go to the big chain ring. Maybe bottom out all your adjustment screws... then back them out a few turns and set it...
I just checked the lx derailer on my office bike.. i can get it to go out to 2 3/32 of an inch (well, it hits the crank arm and stops) it could go further