I updated mine with the firmware from Repetier: [
www.repetier.com] . There is a wizard that walks you through it, but it might help to save off your eeprom (internal config settings) before you try to replace it. If they gave you the source code for your original then even better as you have a fall back to start over.
The only problem with their software is that now you have to make a donation to download (which is fair really). If not, you can always use MatterControl to send the commands (and slicing).
~b