How can I test for a summary vs. node page?

I am trying to get the title to display on summary pages (e.g. taxonomy/term/18) but not on the individual node pages. (because I display the title within the node itself and I don't want a duplicate).

I read in thread 9984 that I could use the $main variable to test whether or not I am on a main or summary page.

So in page.tpl.php I put the following:

				<?php if ($main != ""): ?>
					<?php if ($title != ""): ?>
						<h1 class="content-title"><?php print $title ?></h1>
					<?php endif; ?>
				<?php endif; ?>

But I can't get it to work, and I don't see any other variables in the list of available variables for page.tpl.php list that seem relevant.

Using Drupal 4.5.2 and phptemplate

Any help is much appreciated.