You make it sound like your sort of running half power on the led's, if you have a 48v power supply check to make sure that your getting 48v to the driver. It kind of sounds like your just not getting proper voltage to the led's, kind of like turning the power down to .5. I'm not sure how your set up but with dc you tend to control power via voltage, so if you want full power you would give it 48v half power 24v, etc. it really sounds like your just not getting the full 48v. I'm not real solid on this stuff so take it all with a grain of salt. It's too bad Evil66 isn't around he could solve this in a heartbeat.