I have an intermittent problem with the checkout page slug changing by itself from "packages" to "packages-2". The checkout page still works with the new slug, but it breaks menus and other links. The problem seems to happen when I change other Pro Sites settings. It's not 100% reliable, but this sequence seems to cause it.
1. Set up Pro Sites
2. Set up some levels
3. Enable Pricing table
4. Enable Feature table
5. Add some features
6. Rebrand Pro Sites: Pro Sites -> Packages
7. Go to: Pages > All Pages
8. Quick Edit page title: Packages -> Website Packages
9. Leave slug unchanged as "packages"
10. Make several changes to Pro Sites settings (don't change Rebrand)
10.1. Change Signup Message
10.2. Change Free Trial Disabled/set
10.3. Change Levels: Is Visible