Sorry for the very late reply, I've been rather busy at the moment with other deadlines for university as the end of term is fast approaching!

Yes it is definitely the same material assigned to the head and the body. I have only created one lambert with this chequered pattern. At first I unwrapped the head and body UVs so that the were still attached to each other, and this problem occured. I figured maybe I could try separating the head UVs from the body so that I could scale them down, but this doesn't seem to have any effect on how the texture appears. I'm hoping that there is some simple option somewhere that I've overlooked on account of being a newbie! Can somebody help me fix this please? Thanks.