When exactly do you get this error? In the designer or while trying to execute your query on the server?

If the error occurs in the designer, be sure that your library (ojdbc14.jar) is in this path : <XAware.Home>\dynamic\jars

If the error occurs on the server, be sure that your library is present in the classpath.

For example with the standard all-in-one installer, you get a Tomcat server. So for your application to work, you need to put your library (ojdbc14.jar) in the folder :
<XAware.Home>\apache-tomcat-6.0.16\lib
or
<XAware.Home>\apache-tomcat-6.0.16\webapps\xaware\WEB-INF\lib

and then restart your tomcat server.

Hope this helps you.