If you copy your recordings from the recording directory to a safe place (safe meaning a folder not related to mediaportal) then you can uninstall mp and then install the new version and then copy back your recordings to mp's recording folder and then go into tv-server configuration/recording settings/database import and then your're recently added files to the recording directory can be imported and after that they will show up in recorded tv. About the scheduled recordings I don't know.
//johnzered