I have a 2650XM router that I just upgraded to IOS 12.3(22). When I make changes to the config. and use either "write mem" or "copy run start" and then reboot, it boots back to a default config. After making my changes I can do a show run and see the changes, and then after saving them I can do a show config and see the new configuration. However, once I reboot the changes are always gone and it acts like a brand new router. What am I doing wrong or what might be wrong with the hardware?