Remote Buddy requires its driver to be loaded for any access to real 
hardware (including the Apple Remote IR Receiver). If you have an old 
version of the Remote Buddy driver installed, newer versions will not 
use it, but instead prompt you to update the driver. Once you have 
updated the driver, Remote Buddy uses it and can access the hardware 
again.

Regarding the "Testdrive" option in the driver Setup Wizard: it is 
currently only available under Snow Leopard when no previous/old 
version of the driver is installed.

Here are the two options available under Snow Leopard:

1) Use the "Uninstall" option to uninstall the old driver version 
already installed on your Mac. Reboot , so that changes can take 
effect. Then choose "Testdrive". It should work fine.

2) Use the "Install" option to upgrade the old version of the driver 
to the latest version. Reboot, so that changes can take effect.

Best regards, 
Felix Schwarz