The next time you start bitching about "grammatical errors" that set your teeth on edge, have the decency to make the things you complain about actual issues of grammar. Grammar is a somewhat vague term, but it certainly includes syntax, as well as a good chunk of morphology. And a case can be made for certain parts of semantics. But spelling errors, such as the confusion between "affect" and "effect," certainly aren't grammatical problems. And I would argue that most questions of word usage, that is those that turn on pure semantics (e.g. confusing "flaunt" and "flout") as opposed to those that have a syntactic component like complement structure (e.g., "prevent them to go" vs. "prevent them from going") don't count either.
Lately, I've started to seriously entertain the notion that the term "grammar" should be given up as a hopeless cause. It has been so thoroughly compromised by pontificating blowhards that it should be abolished from serious discussions of language altogether in favor of a more specific indication of what aspect of language we are really talking about. Leave the term "grammar" to the those who fetishize Strunk & White and who have no idea how to distinguish sound writing advice from the idiosyncratic crankiness of long-dead writers who don't even follow their own pronouncements.
Sorry for ranting. I've been reading forum threads that I should know to avoid. But sometimes, when someone is wrong on the Internet, I can't help myself.