Within the last 48 hours of this post, the Project Administration (PA) interface and underlying code has been swapped (e.g. https://sourceforge.net/project/admin/public_info.php?group_id=254159 ).
This problem report is about the "Project Homepage" field.
Previously, I believe, the static text string "http://" was put in front of the "Project Homepage" HTML form field. (Not inside the field as a default value, but really before the input element.) So project administrators just entered the non-protocol part, e.g. "xtables-addons.sourceforge.net".
With the new code switch that just happened, that http:// prefix is gone, not only from the view, but also from the actual underlying logic code, so that the "Summary > Web Site" link is <a href="xtables-addons.sourceforge.net">, which is wrong, because it is then interpreted relative to the SF project page.
This affects *ALL* existing projects.
Proposed workaround: Add http:// prefix - if it is not already present - when the project homepage link is read from the database.