That sounds like it may have been a mistake. I think they were all supposed to be signed, and some were personalized by request. They all should have been stamped and numbered as well. Does yours have a stamp and number? It would be on the same page.
Hi – hopefully this post triggers alerts to all of you who had questions regarding the wiki.
The wiki is back up and running and detailed instructions to participate can be found at this link: http://scottsigler.com/forums/topic/siglerpedia-wiki-alert/.