PgFoundry.org went down some months ago, I contacted webmaster Marc Fournier and he was able to get it back up but a lot of it no longer works and I don't think he responded to my follow-up. For the most part top pages are broken but sub-pages are still there (just very hard to navigate to and find).
If you are looking for something specific you will need to google for it rather than navigating through
pgfoundry.org. For your example (Sample Databases) I googled "site:PgFoundry.org sample databases" and I think the first hit is what you are looking for:
http://pgfoundry.org/frs/?group_id=1000150. You'll notice that you can navigate through the other sub-pages in that project but if you go to the Summary page it will be broken.