What version are you running? If it's not the 1.1 version of the Thinkdreams theme, which has been upgraded to support all of the new features (by the error looks to be the case), you may want to try the new version. Make sure you are also running Zenphoto 1.1.2, which is the latest version of the core code.
You can get the new version here (and browse all the other themes too):
http://www.zenphoto.org/themes.php