Blog Template Plugin Error

Hi

I have configured your plugin on my blog running wordpress version 3.0.1. Everything appeared to be functioning correctly until I attempted to create a new blog using one of those templates using an email(user) that already exists is the DB. Once I click "add site" a white page appears with the error "Notice: Undefined index additional_tables in "\plugins\blogtemplate\blogtemplatesfiles\blog_templates.php" line 367. I haven't modified any of the core plugin files. The create site with an email not in the DB works. Any thoughts?