[Plugin: Yet Another Related Posts Plugin] YARPP 3 b3: templates don’t work

I have a problem with the new template function.
As soon as I enabled a template it did not show up in my theme (but it works fine without a template). The widget in my sidebar only showed the heading but no related posts. I got no warnings and no errors.
My folders are installed exactly where they should be as stated in the install.txt.
Then I removed YARPP and everything related to it out of my database.
When I do a clean install of YARPP I get errors showing up in my Apache error log:
Duplicate key name ‘yarpp_title’
Duplicate key name ‘yarpp_content’
And something with the following, but it does not say whats wrong with it:
CREATE TABLE IF NOT EXISTS wp_yarpp_keyword_cache
CREATE TABLE IF NOT EXISTS wp_yarpp_related_cache
Those errors only appear when I activate the plugin.

Next I disabled other plugins and found one that was hiding warnings in my theme.
So with a template enabled I get now these two warnings in my theme:

Warning: include(../yarpp-templates/template-list.php) [function.include]: failed to open stream: No such file or directory in G:\!Xampp\xampplite\htdocs\wp\wp-content\plugins\yet-another-related-posts-plugin\magic.php on line 260

Warning: include() [function.include]: Failed opening ‘../yarpp-templates/template-list.php’ for inclusion (include_path=’.;G:\!Xampp\xampplite\php\pear\’) in G:\!Xampp\xampplite\htdocs\wp\wp-content\plugins\yet-another-related-posts-plugin\magic.php on line 260

My WP 2.7.1 is currently running only on localhost, so I can’t give a link to you.
Unfortunately I have no clue of PHP, so I can’t fix it myself. Any help would be appreciated.

Greetings,
Manu