Guys,

Thanks for the replies.

Just as you pointed out, this was a case of editing the model after the UV map had been made and not updating the UV map to accommodate that change.

I didn't realise that the UV map needed updating as I didn't think I had changed the model from the original. I thought I had just replaced an existing part of the model. You live and learn.

I didn't get a chance to sew the UVs as I had to redo the entire UV map to accommodate some bigger changes.

Your help is much appreciated.

Cheers

Tom