If I search for 154 I get good results, but then if I search again from the search box on the search results page for 155 it searches for something like this and returns no results.

(\"154\") AND (155)

or in the case of words, if I search for share then something I get
"Sorry, no matches for (share) AND (something). Try refining your search."

What do you think is going on here? Thanks.
You can try it at http://share.gospelriver.com

Zenphoto version 1.4.1.6 [8326] (Official Build)
Current locale setting: en_US.UTF8
Current gallery theme: Effervescence+nb
PHP version: 5.2.17
Graphics support: PHP GD library bundled (2.0.34 compatible)
PHP memory limit: 200M (Note: Your server might allocate less!)
MySQL version: 5.1.60
Database name: mysitecrznp2
Table prefix: zp
Spam filter: simple
CAPTCHA generator: zenphoto

What's happening is the second search is searching the results of your previous search. You need to click the reset icon (ball of fire) to do a new search.