Rated 5 out of 5 stars
Hi Jennifer, yep, great extension, beautiful and deadly!
Buuuuut, after upgrading to 4.0.1 I am justing getting a blank window where the source used to be displayed. (It was working fine before the upgrade.)
Any ideas? Here's hoping!
Tools > Add-ons > Extensions > View Source Chart > Options (Preferences) > select "View Source Charts in a tabbed window"