Which source are you using? What OS? Any other info that you think might be helpful.
Edit: I just tried it out here and didn't see anything like that ... seems to be saying some source/header files not found?
I'm on Xubuntu 13.04. I am using the most recent Namecoin code (in the namecoin-qt branch) as of now. Here is the latest entry from 'git log':
Merge: c540853 a9c69f2
Author: khalahan <
khal@dot-bit.org>
Date: Mon Jul 1 12:11:55 2013 +0200
Merge branch 'namecoin-qt-snailbrain' into namecoin-qt
Thank you.