Pandora, be aware that My Japanese Coach has a rather significant number of errors. こんにちわ would be one of them (though I don't actually remember hitting that).
I bought a copy a while back to evaluate it, and my 10-year-old daughter spent some time with it. You mentioned that you're using it to learn the grammar, and as far as I remember there were no real problems with the grammar from that program; however, it teaches (and forces) you to us incorrect stroke orders for a number of characters, and in the case of some of the kanji, it completely butchers them (山 for instance).
Basically, it's an incredibly great method for learning, but with unfortunately very poor-quality material. It's fine to use, but realize you'll have to relearn some things (and you should especially check your writing against more authoritative materials).