Probably to do with the shape of the viewscreen Nif. I've noticed that you're not terribly picky about the positioning and size of the viewscreen nif. It appears to be a couple of meters inside the K'tinga bridge, and there are some slightly off-centre or odd loading screens I've noticed on other bridges that probably have something to do with it.
It's totally understandable with the shuttle bridges, and may not be something you noticed after a few of those, but it is important.
Trimming it to shape and positioning it so it fits snugly in the viewscreen fame here ought to solve this problem.
Luckily, I don't think the viewscreen Nif suffers the same problems as the bridge nif in terms of model format issues.
I was able to tinker with the Galaxy class viewscreen, even added spheres and cubes in random locations in the name of research. When the screen was "active", this just had the effect of stretching the image to cover the visible width of the nif, but the loading screens actually visibly mapped to the nif, rendering z-buffered along with the bridge geometry, rather than behind it, as with the "active" screen.
I still think you're awesome
just a bit of friendly advice. When I get back to my own PC, I might knock up a viewscreen patch-pack for you if you like? I should get back in a few days.
EDIT
Friendly advice which, re-reading back on your responses, you're probably quite aware of...
A further edit to say that if I'm wrong about the above, then apologies will tumble from my fingers with potentially irritating rapidity.