Thanks for the quick response! I JUST figured it out. I've been working on it for 3 days... :-)
The ad I had placed under the original block-leaderboard-ad had automatically been 1000px wide, which is too wide for that area on the asset pages. It was also in the Index-top-featured content area. I moved the 2nd ad block underneath the original block in the top global container - NOW IT WORKS!
Thanks for responding so quickly... I hope this helps someone else that needs MORE ad spots!
Customer support service by UserEcho