Since it gets more noticable from further away, might it be a problem with the mipmaps somehow? I definitely didn't see it at all in the techroom using those textures yesterday.
Could be a mipmap related issue. But you can actually test that in the lab too, just by zooming in/out it will switch mipmap levels. Viewing it in the techroom may just use a mipmap level so small that you can't notice it (depends on the filter used to create the mipmap levels). In the lab you have a little bit more play to try and figure out where a map problem might be, but since the background is black, it's usually pretty difficult to actually see those problems.
The background problem in the lab is something that is on my todo list to deal with though, along with setting of light color/position, number of lights, and the envmap to use.
