If I come within draw distance of lights and then head away, my avatar remains lit (albeit increasingly faintly) even when I'm far past the point where it should be. As an example, at one end of my sim, I have a building with six lights in it, each with light radii from 5 to 6. I can fly all the way to the other end of the sim and my avatar will still be faintly lit. (I've included two images of this, both with all ambient and sun/moon lighting turned down to zero. The brighter image has the gamma cranked up, so you can see better. It's subtle, but if you look you can see that she's being lit from the front.) If I log in while at the other end, though, I don't have this problem until I get close enough to the lights for them to rez. The dim lighting in the pictures isn't a huge problem, as it's hard to notice unless you're looking for it, but the lighting becomes obvious when I get closer, even when I still should be out of range. This problem does not appear to be limited just Windlight and just avatars, but it seems to affect the Windlight avatars particularly noticeably.