Lux bug: Her ultimate doesn't properly calculate Illumination proc damage

Found this on Reddit, and I have been noticing on occasion that my laser isn't doing the damage it should when hitting a target affected by Illumination.

Please look into this, Riot.

Oh, and while you're at it, can you consider lowering the mana cost of her E a bit? She gets less mileage out of it than a Xerath, so I don't think her primary damage skill should cost more than his.