The jdbc driver that ships with kettle 2.2.2 (mysql-connector-java-3.1.7-bin.jar) is rather old and buggy.
You can notice right away when editing Kettle steps from where you can pop up a database table browser. For MySQL 5.0 databases, the browser shows a views node and a tables node, but both tables and views are shown beneath both these nodes, whereas the tables node should only have table nodes beneath it and the views node should only have view nodes beneath it.

To solve that problem, at least for Windows XP, do:

1) download the most recent GA Connector/J from the download page at http://dev.mysql.com/downloads/connector/j/3.1.html

2) unpack the downloaded distribution

3) copy the .jar named mysql-connector-java-3.1.12-bin.jar (or newer) to the libext directory located directly onder the kettle-2.2.2 installation directory

4) open the spoon.bat file located in the kettle-2.2.2 installation directory in a text editor, and locate the line that goes:

set CLASSPATH=%CLASSPATH%;libext\mysql-connector-java-3.1.7-bin.jar

5) modify that line so that it reads:

set CLASSPATH=%CLASSPATH%;libext\mysql-connector-java-3.1.12-bin.jar

(obviously, if you downloaded a jar with another version number, use that filename here instead).

6) repeat steps 4 and 5 also for chef.bat, kitchen.bat and pan.bat

That should do the trick.

(For *nix users, the procedure is probably similar)