oemuni OEMTextOut doesn't hook

Hi everybody,
Please can you help me?
I'm dealing with Printer Driver example (oemuni in oemdll WinDDK) under
Windows XP, and WDK samples Index says: "The basic hook for OEMTextOut has
already been implemented"... After building the example, I'm able to debug
the codes but I can't understand why OEMTextOut doesn't hook. Itried to
print with Notepad (simple text) and other applications but OEMTextOut has
never been called.
What's wrong? Am I missing somethings?

Any suggestions will be appreciated.

--
Davide Basso