First of all, thank you for this amazing plugin! It's easy to use and to customize for my needs.
I tried to use it with the latest WP E-Commerce plugin and the page crashed whilst being on single product or category page. It took some time but I fixed the issue by changing line 329 in "index.php"
$promo_posts = get_posts( $query );
$promo_posts = query_posts( $query );
And it fixed everything.
So this is a fix if anyone is experiencing the same problem. Hope this helps!
Also, Micah, please look into it :)