My Analysis: Don't take this as gospel, but what I think happened is this:
The original text block contained an image, with the shadow effect applied, followed by text. (I don't think Firefox renders the javascript shadow effect). The classes applied to the image contained .tinyText which is:
.tinyText {
font-size: 1px;
line-height: 1px;
}
and that got carried over to the following text. Encapsulating the text in a nested text block protected it. Why it happened in some areas on the page and not on others is unknown, but with a work-around, I don't care.