Prusa XI3 not printing correctly with Repetier Host
In order to try a short answer even though you already found a change to Cura helped the issue. With that additional info we can conclude that your printer per se is working fine. To me, if the plastic is curling up to a ball, it seems that you are either having


a wrong temperature set
wrongly calculated e-steps, volume calculation (filament diameter) or multiplier in the firmware
additional first layer parameters are off (height, offset, extrusion)


You can try to set the extrusion multiplier just to test if it is a simple miscalculation.