Recently, the FFXI world servers (especially Ragnarok it seems) have experienced numerous problems including auction house failure, search failure, and inability to login to FFXI completely. The reason was anyone's guess until now.
http://www.playonline.com/ff11us/polnews/news4410.shtml
Edit: I missed it earlier, but this info was also posted on the homepage of this website.
Edited, Fri Apr 15 20:28:22 2005 by Ieatcats