Apologies if this has already been mentioned. I only had enough time (if had to be honest, was lazy, as well) to quickly search the thread.
For those using Durante's 4xSparseGrid Inspector hack, I noticed there was a glitch that will cause shadows around lighting to break producing broken lines that crawl and flicker. There's an easy fix for it. Under the 'Antialiasing fix' setting, just select and apply the Team Fortress 2 flag and that's it, problem solved.
Inspector settings:
Untitled by
vincentric, on Flickr
Love the game, have been spending most of my free time on it, am further along into it now I've reached the huntsman's copse area.