Indoor Textures:
I also noticed occationally in the houses/ buildings in ald'ruhn the whole screen will be come a solid colour when I look at a random location, this doesn't happen all the time but when it does you can't see anything but a solid color. Any ideas what's causing this?

I also have this happen to me. It seems to happen more often while sneaking, with a lower POV. One place I see this reliably is at the top of the lighthouse in Seyda Neen, looking at the pair of barrels (indoors).
Maybe this is Nvidia black screen bug, try this
http://www.tesnexus.com/downloads/file.php?id=11167
This solved my problem Nobeus, ty.
Curious that this bug never affected me in base Oblivion.