Using the Default PCF will take you back to the factory supplied configuration.

It sounds like you replaced the action on the Lights button with an IR Code. You need to use the Pronto Edit sotware to change the action back to a Jump.

Also, it is easier to learn codes from the Pronto Edit software. On some (usually older) computers this does not work too well. If that happens to you, download your config to the Pronto, learn the codes directly on the Pronto, then upload the config back to your computer.

Also, make sure you are using the latest version of Pronto Pro Edit NG, and firmware. Older versions have problems.