[Zope] Var Problem

[Ben Ocean]

Hi;
Real basic newbie question here. I've got this dtml:

<span class="header"><dtml-var header></span>
<span class="bar"><dtml-var bar></span>

They're both images in the *Images* file (I'm using PTK). Now, *header*
shows up just fine. *bar* gets a KeyError. If I change the name of *header*
it chokes, too. What gives?
TIA,
BenO
P.S. All the CSS is written in the standard_html_header.