Just picked up another used D300 to replace my older model. Previous owner had 1.10 and 1.00 running on the firmware. Upgraded to 1.11 without a hitch. Be aware, 1.11B is 7MB compared to about 512KB for A. It will take a while to install B, so don't panic if you don't see movement on the progress bar in the beginning. Make sure you've got a fully charged battery!