fatal error memory size

Hi,

Thank you for the great plugin!

I installed it on a blog and [sbs_pages] works but when I tried to use [sbs_posts] the error below appear:

Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 20480 bytes) in /home/brazenbull/public_html/macisaac-blog/wp-includes/wp-db.php on line 1972

Would you be able to help me? I really like the plugin