Don’t label a label!
Just a quick note: I was fiddling around with forms – styling them, making them all sweet and pretty – when I stumbled upon IE7 being the only browser (out of FireFox, IE6, and IE7) which for some reason hid the labels.
I realized that I actually had ended up with a bunch of labels within another label, and I fixed the problem by deleting the outer label.
So if you're having the same proble, try deleting the outer label tag and see if it works.