CPU V.S GPU issue

Hey guys. I ran into something the other day. I decided to try using the GPU renderer instead of the CPU to increase performance, but the result I got was way wrong.
CPU:


GPU:


I have an Nvidia Geforce GTX 560M with 2GB dedicated RAM.
My laptop has 8 GB System RAM, a second gen i7 processor.

Is this my computer or a bug in blender? (The issue did seem to come around after the GPU renderer switched from CUDA to openCL)

(The issue did seem to come around after the GPU renderer switched from CUDA to openCL)
OpenCL is not currently fully supported. Why are you using it instead of CUDA ?