It doesn't actually look like you've upgraded. From the look of the watchlist page you're still using 1.5.0. Can you check the system settings page and confirm?
Hmmm this is what it says, This Mango version 1.6.0, but I did have issues with the upgrade.
I saved a copy of the root directory at the same level, as "copy of root" then over wrote the root with the new version. When I restarted it used the "copy of" directory to recreate the work directory. I then deleted the work directory again and the "copy of" directory and restarted tomcat.
I guess what you will say is that I need to reinstall