I can't remember the exact place I saw this (but I believe it was on another StackExchange site), but when someone was commenting on a software's "spell check" function, they said something to the effect of:
A spell check is something I do with my local coven, a spelling check is what I do when I'm reviewing a written document.
Is it more correct to say:
This paper is horrible! You didn't even use a spelling check.
as opposed to
You didn't even use a spell check.