This one reaches the "root" of the nodeset. Therefore this does not work:
>      <xsl:variable name="acronym" select="$acronyms[1]/@acronym" />

Right now, you are looking at the first acronyms element (there is
only the one).
Your variable would have to look like this "..]/aconyms/acronym"

Regards,
Ragulf Pickaxe :-)