hey guys. thanks for the useful suggestions. i have since fiddled with a lot of the light and shadow settings but with not much luck. it took a while by i have finally nailed the problem! it's im the material. i used an arch & design matte material i think and it was relfecting the light off of itself like crazy! have a look at the image below;
the walls are no longer bouncing the light off like before... i have left the ceiling as it was to show the difference. look at the irregular colouring and the lack of shadow!