I have same trouble you describe with adding repos. But lots of other links don't work either, so I ignored it. Example: go to nokia's OS2008 user page and follow link to UKMP, a 'recommended app'. You get

Server Error

Component org.openpsa.products failed to handle the request
Error 500
maemo.org
Fri, 16 Nov 2007 01:37:31 +0200
Apache/2.2.3 (Debian) DAV/2 PHP/5.2.0-8+etch7 mod_ssl/2.2.3 OpenSSL/0.9.8c Midgard/1.8.4

Stacktrace:
1: /var/cache/midgard/midgard/7-49-31-0.php:0 {main}
2: /var/cache/midgard/midgard/7-49-31-0.php:160 midcom_application::codeinit
3: /usr/share/midgard/svn/midcom/trunk/src/midcom.core/midcom/application.php:571 midcom_application::_process
4: /usr/share/midgard/svn/midcom/trunk/src/midcom.core/midcom/application.php:1006 midcom_application::_handle
5: /usr/share/midgard/svn/midcom/trunk/src/midcom.core/midcom/application.php:1113 midcom_application::generate_error