David :

Welcome to the forum and glad you posted. Look at the PB link below esp. at Dave Willis comments . The PB mag. has included several articles on BG spawning etc. and I would suggest you subscribe as I think your point will be covered shortly.

http://www.pondboss.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=20;t=002198