I'm trying to update my Astro 430 but when I restart the device it will not install the update.

I've tried using WebUpdater and Express, I've tried different USB cables, and I've tried different computers. The programs tell me the update was succesfully transferred to the device but when I restart the GPS it boots like normal without installing the update.

It's currently on version 2.40 and the update would be for 2.50.

Thanks for any help!