In general, people should get it into their heads that p3d is never going to be an accurate representation of what you'll see in FSO. Polygon errors are great to report, but weird texture stuff should in most cases be ignored. For one thing, p3d doesn't do glowmaps. p3d just renders things differently than FSO will.
Granted p3d is still a pretty new tool for us to use to be showing WIP models, so there will be some 'training of the masses' to do on it yet. So today's lesson, to summarize, is that you should almost always ignore weirdness relating to glows when viewing in p3d.