N91 abuse
critical_limit has asked GSM Forum for help after attempting to downgrade an N91's firmware - the result was a device that could not even be switched on. This issue has been raised before...
You cannot downgrade the firmware on an N91 and, if you wish to upgrade your firmware, use a Nokia service centre. Please do not attempt to upgrade/downgrade the firmware on your beloved N91 at home.
To see why click here.