Java EE (Java Enterprise Edition) General Discussion

Used software:
- Tomcat 5.5.11
- JDK 5.0
- Windows XP SP2

Problem statement:

I have a webapplication, called monitorclient, which uses a connection
to a database using a JNDI bound DataSource object through my context.xml file.
To connect to the database (SQL Server), I need several JAR files. Whenever I
place these JAR files inside the ${CATALINA_HOME}/common/lib directory,
everything seems to work fine.

However, I would like to place these JARs into my webapp's lib directory, which is:

${CATALINA_HOME}/webapps/monitorclient/WEB-INF/lib/

Whenever I do this, the driver class ...

com.microsoft.jdbc.sqlserver.SQLServerDriver

... seems to fail to be found.

The generated exception is:

javax.servlet.jsp.JspException: Unable to get connection, DataSource invalid: 
  "org.apache.tomcat.dbcp.dbcp.SQLNestedException: 
    Cannot load JDBC driver class 'com.microsoft.jdbc.sqlserver.SQLServerDriver'".

I've read the Tomcat documentation about classloading, and I can't seem to find
any errors from my part. I queried the forums and google about this matter but
I don't seem to get any results.

Directory structure:

${CATALINA_HOME}
  /webapps/
    /monitorclient/
       /META-INF/
          context.xml -> has the DataSource
       /WEB-INF
          /classes/
            /com/.../[some java code]
          /lib/
            msbase.jar       --> when I place these jars here instead of in
            mssqlserver.jar      ${CATALINA_HOME}/commons/lib, classloading 
            msutil.jar           seems to fail.
     index.jsp
     blah.jsp
     [...].jsp

Any help, pointers or the like are greatly appreciated.