I found a work around that works for me in this thread:
http://forum.bytesforall.com/showthread.php?t=177
It is not exactly the same thing as to have the first post displayed as full, but it can have a similar effect. I thought this might be useful to you too, until a better solution arises.
In short, you install the "
Category page" plugin, which allows you to add a page content on top of a category page, and you do this:
1. Select the file named Main Index Template (index.php)
2. Look for the following code :
<?php /* If there are any posts: */
if (have_posts()) : $bfa_ata['postcount'] == 0; /* Postcount needed for option "XX first posts full posts, rest excerpts" */ ?>
3. Paste the code listed below just after,
<?php if( is_category() AND function_exists('page2cat_output')) { page2cat_output($cat); } ?>
4. Click Update File
Note: To link a page to the category there must be at least one post in that category. If the category is empty the plugin connection does not work.
I am using Atahualpa 3.4.4 and WP 2.8.6
Good luck!
M-J