I installed Version 10 and used it on an update of our personal collectibles, site, IHateSnakes.com.

On the site we make extensive use of pop-up layers and images to showcase the items in our collection. With 10, ALL of the pop-up layers and images ceased to work.

When I switched back to Version 9, the problem disappeared.

Seems like a significant issue to me...

Richard
Diamond Pacific Media Group