I am unable to reproduce the 'back' icon as I can tap it fine here and it takes me back to the switchboard (main screen). As for sync'ing, if you have the PDA Companion licensed, and license code entered on both the PC (under PDA Companions\Palm Companion menu) and PDA, you simply hotsync it and it will sync the PDA data to the PC.
It is recommended to use the CrossFire client version of 1.9.8.1 Palm Companion with the Treo 650's.