You should not have a problem. But you should always be prepared for something going wrong; have you used John's NVRAM Save and Restore Utility? That would allow you to back up your settings so that they could be used not only on the same router with a different firmware version, but even on a different router (with careful reading of the instructions). In contrast, the backup/save settings feature in the router's gui allows you to backup your settings, but that backup should only be used on that router and with the same firmware version it was made on. So, if you were using that method and you had a problem, you'd need to revert back to that previous firmware. On the other hand, John's utility is far more flexible and is worth the time it takes to read and thoroughly digest the Quick Start guide that comes with it.