EasyC - Running several US range finders

EasyC - running several ultrasonic sensrs at the same time
When i tried running several ultrasonic range finders one after the other in the same program it was getting allot of buggy entreis in the distance output of the terminal. its not a matter of signels colliding (i made sure it wasnt) but i think its either to do with EasyC or the Cortex, is there any way of getting two diffrent sampels of distance with two diffrent US finders?