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What is the difference between network mode GSM and network mode Dual? I have got a nokia 6630 and in network settings i have got two options. Network mode GSM and network mode Dual. Both seam to work very well so i don't understand what is the difference between the two and which one should i choose. Dual was the defolt choice but by swiching to gsm doesn't seam to make any difference. Thanks in advance for your help.
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