Firefox and Null XML?

I have a bit of a problem. I'm trying to use the control to bind some XML into a grid on firefox 1.0.1.

This is my XML file (structure copied from the example):

<TEST>
<row>
<name>elvis</name>
<number>4</number>
<rank>general</rank>
<id>3C9DV2NTQqOSfnb6aYS8mA==</id>
</row>
</TEST>

With the above xml file, my grid draws perfectly in both IE 6.0 and firefox.

However, it hangs on "loading data please wait" if elvis (above) has no rank e.g.

<TEST>
<row>
<name>elvis</name>
<number>4</number>
<rank></rank> <!-- null node -->
<id>3C9DV2NTQqOSfnb6aYS8mA==</id>
</row>
</TEST>

I can make it work if I change the "rank" node from null <rank></rank> to a "space" node e.g. <rank> </rank>, so I'm assuming this is some sort of nullality issue. Anyone have any suggestions on how to resolve this (and, no, changing the XML isn't an option as I don't have control over the format, it's going to have nulls in it sometimes).

Anyone?

What if <rank></rank> is <rank /> ???

Not sure, but seems to be a solution in :
http://activewidgets.com/javascript.forum.1164.12/cannot-display-grid-with-mozilla.html