Resistive touchscreen with 5-wire connection & Freescale IMX28
I'm just spit ballin here but why would you connect RL to LR if you've connected RT to UR?
Swap UL and LR connections and see what happens. It just seems like you would connect the L's to the L's and then obviously SG goes to wiper, so that leaves the U's to go to the R's so put RL and UL together.  

I can't find any documentation related to the touchscreen mentioned so this is the best I got.