icxmy: Hmm interesting, are you sure this is caused by FastCraft? Something is modifying the view matrix without resetting it. It may be just a coincidence.
Thanks for responding.
No I am not sure this is a FastCraft issue. However it did go away when I stopped using FastCraft and came back again when FastCraft was installed. I suspect there's a conflict with another mod. My daughter asked for the DoggyStyle mod to be installed a day or so before I noticed this issue. It could be something to do with that as there were dogs roaming around at the time.
I have now moved the dogs from that room and the issue is no longer happening with FastCraft installed.