At the moment the data from the lite version will not be transfered to the pro version if you update. Until I create a function for this you can use this workaround:
After installing the pro version you can copy the “database.sqlite” with iTunes on your computer (Device -> Apps -> Scroll to the bottom) from the free version to the pro version.
So you start with all cache lists and caches in the pro version. After copying the database you have to authorize your account with geocaching.com in the configuration again. Also the configuration settings are lost.