You don't say which application you have been using to sync your T5 with ACT. I'll assume it's ACT link? Maybe you have just purchased and installed ACT??
If so, and you have data in your Palm that you need in your ACT database, why not sync the PIM data in your Palm with the Palm desktop and then export the data out of there, creating a file you can then inport into ACT?
Be sure to make a backup of your T5 data first with something like NVBackup. If something screws up - just reset the T5 and restore the backup.