I just upgraded the List Category Posts plugin from .17 to .18.3, and it broke my customised template :(.
My setup: WP 3.0.4 multisite network enabled, local installation with MAMP, PHP 5.3.2.
LCP plugin installed automatically. Works fine with the default template. However, you've rewritten the code such that the template had to be rewritten also.
I've managed, with a bit of a struggle (not strong in PHP), to tweak the default template and save it as my own customised template, and now it's displaying as I want.
I think this needs to be pointed out in documentation accompanying the updates.
One feature you've added - which I really appreciate - is to allow access to templates either in the parent theme or child theme. Thank you, this is working very well, and the best solution to the problem of whenever we update Wordpress.
Now, if only I can get the thumbnail to display. :(