Shadow Fall graphical annoyance

The /dark power, shadow fall. I took it on my mastermind and I think, as a stealth power, it's meant to turn you transparent. The problem is when turned it on it looks like this -



Maybe not the best shot, but you can see the chest area turns very blocky, instead of see-through as I think is intended. Has anyone had this issue before, or know of settings I could try? Might not seem like much, but it annoys me so badly I won't use it currently.