Is there a glitch for vampires that makes it seem like you are in sunlight even when you are in a cave?

Not that I know of.

Thanks.. I think it is because it considers blackreach outside.. so if its day it affects me.

Yeah, Blackreach is underground, but is considered outside. Doesn't make any sense.

Same thing happened to me in Labyrinthian just last night when I was doing "The Staff of Magnus." I was in a cave but I still got a message about the sun and such. I figured it was because there were some holes where sunlight peaked in and I could hear the sound of wind howling to denote direct exposure to the outside, but Blacksreach is pretty much way the hell underground. I guess it still counts as "outside" since there's a ruin within it but that still seems silly.

Yeah no kidding.. It made fighting in there as a low level vampire mage very tough.. Lol no regen.. But I got through it! Lol