Got a replacement phone at the weekend (through insurance), got my K800i replaced with a K770i (vodafone). Lovely phone but pics in dark environment no way as good as K800i. Anyways, firmware updated yesterday morning (i'm in UK) Unable to send or receive calls for a few minutes at a time. At work where there is good 3G coverage there is no problem, but at home the coverage is ok the phone is unusable unless I go into the settings and switch to GSM only.
K770i. any ideas anyone? How could I 'go back' to firmware version?

Please help

I did not find the right solution from the internet.

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