NPC sell orders for starbase structures have been temporarily disabled (http://www.eveonline.com/news.asp?a=single&nid=3918&tid=1)
29 May 2010, 1:15 pm
During downtime on Saturday, May 29, all NPC sell orders for starbase structures, sovereignty structures and station components were temporarily disabled. These orders will be restored temporarily on Wednesday, June 2 until Planetary Interaction is fully operational.
Source: eve-online.com | news from EvE (http://www.eveonline.com/)