I've been putting this off for a few months now. I don't remember when it started happening. Basically, at a certain distance all around me, exclusively on terrain and world-based water (i.e., not bricks) I get a bunch of colored lines at a certain distance. These lines are always at a certain distance and move with me, etc. This has been happening for a long time, even before v21 was released.
Recently I also noticed something a bit similar was happening with a weapon, but I'm guessing its just the model. I'll post pictures of both, anyway, because they seem related.
The lines as a group are always one color, but aren't always quite the same color. Somehow I doubt that matters, though.
I'll need to get some pictures later. The ones I have right now are just over the 512mb limit, and I don't have time to resize them right now...
Has anybody else had an issue like this?