I just tried using this and I'm pretty sure I didn't do it right. Where do I enter the code? I put it in the gift code section and suddenly there was almost $400 of stuff in the checkout! But I couldn't see anywhere else in the checkout to enter a code.

Thank you, thank you, thank you!!! I just tried Whispering Grove again and thanks to being able to now see where I was going and what obstacles where in my way I finally completed the quest Now to go back and try out some of those other pitch black caves and caverns.

I'll second this. I've just finished doing The Restless Dead questline and I've developed a headache from having to squint at the screen to make things out. If it wasn't of all the red dots on the minimap I'd have had no idea where the mobs were