Reftagger ≠ Firefox?

Lately I've been having trouble with reftagger. Like at http://community.logos.com/forums/t/45928.aspx.

So this is a test. What does John 3:16 really mean?

Is "So this is a test" repeated above? And is "John 3:16" underlined? Does a tooltip-like window appear when you mouse over the reference? Yes on Safari, no on Firefox? Too bad...