JQuery class selectors like someClass are case sensitive

Question

Given this HTML:

<div class="OpenIDSelector">some text</div>

Why does this JQuery selector match it on some browsers and some pages, but not on others?

$('.OpenIdSelector')

NOTE: I ran into this problem and solved it myself, but it was annoying and I didn't find it on StackOverflow already, so I'm posting it as a Q&A pair so someone else won't waste an hour like I did.

Answer 1

jQuery attribute value selectors are generally case-sensitive.