Hmm odd...
In the "Unofficial piKey 0.4" pack there's something I made called the "Unofficial piKey 0.4 Targus Expansion Pack".
Install that and your application should work fine.
Also, can I ask, what's your firmware?
For an odd reason if your PSP is beyond 3.52 M33, the piKey Sample fails to work. We're trying to figure out why. Just to let you know incase you choose to upgrade.
