Firefox/XML/XSL rendering problem

I'm trying to turn a HTML 4.01 Transitional webpage into an XML/XSLT
webpage, and well, it works, except for one minor rendering problem -
in Firefox, a little space (http://noodley.com/private/ffrender.jpg) -
it's where the red lines go through between some elements of the
design shows - I have no idea why, and with the exact same code, but
as an HTML file, this doesn't happen.

HTML: http://noodley.com/sacrifice/
XML/XSLT: http://noodley.com/sacrifice/index.xml


I'll be *veryyyyyyyyyy* grateful if someone could help me fix it :)