I have a new 2811 which I've configured it a couple of times and seems to loose configurations everytime I perform a reboot. What am I missing here?
Hope you saved the configuration before booting the box :)
If so, check if the config-register is 2142,. If so, it will skip the startup config while booting.
You can verify it using the following command:
Router#sh ver | inc Configuration register
Configuration register is 0x2142