RSS not working

Hello, I have several Galleries installed on my sites, but 3 of the RSS are not working

http://www.omega-sound.com/fotos/rss.php (Gallery v1.5.7)
http://www.alpha-sound.com/fotos/rss.php (Gallery v1.5.7)
http://pichissound.enteratenorte.com/fotos/rss.php (Gallery v1.6-alpha3)

The last one had Gallery v1.5.7, but I toght that upgreating would help but it didnt

I have other galleries on my server working fine, I have around 10 more galeries with no problems, so I dont think that the server or php version has anything to do with it,

Example:
http://gallery.enteratenorte.com/fotos/rss.php

Please advise!

The following information is required to get an answer:
Get this information from the PHP diagnostic (in the configuration wizard).
Apache version: Apache/2.2.3 (Red Hat)
PHP version (don't just say PHP 4, please): PHP Version 5.1.6
Graphics Toolkit: NetPBM
Operating system: Linux Redhat 5
Web browser/version (if applicable): Firefox 2.0.0.13