We all have them, and I'm not just talking about things like procrastination (*shakes fist at Mindjolt and Bejeweled*). What I'm talking about are those things that we *know* aren't right, or could at least be misunderstood, but by habit or preference do them anyway.
A few of mine:
"eventhough" <--- one word, not two. Surprisingly, I don't have issues with remembering to split "a lot"
"more than a little..." <--- nothing wrong with it on its own, but considering I find upwards of a dozen instances of this phrase in any given WIP, it's my kryptonite
"grey" <--- again, it's debatable if there's something wrong with it, but I can't make myself spell the color with an "a". I don't care what it says on the crayon; it looks wrong to me. (Besides, if it was good enough for Gandalf...)
"leapt" <---- (This is an all purpose quirk for any past participle that ends in "-t" rather than "-ed") Apparently, at some point, my Texas English lessons made me spell things the UK way. "Leaped" doesn't look right to me, and I know I hear people say "leapt" with a "t" on the end, but spell check, and American editors, say it's supposed to be "leaped".
Are there any little oddities in your own habits that irk you?