Would it? Seriously, I don’t think there’s anything incorrect about “grammar errors.” Could be wrong, though; wouldn’t be the first time.
Well… now I’m not so sure. I’d think that ‘errors in grammar’ or ‘grammatical errors’ would be proper… ‘grammar errors’ just sounds wrong to me, but I’ll admit that I can’t pull a rule out of my word horde to justify my groking wrongness. Hrm… we do say ‘spelling mistakes’. Hrm…
Er, I mean, motherfucker! We’ll settle this with pistols at dawn!