Top Twin Card on NOKIA 6600

[Just buy a nokia 6600 and a duble sim support.
The feature work poerfectly on Panasonic GD 90 and Motorola TIMEPORT.
The duble sim support seller said it works perfectly in two ways on nokia 6600:
1) turning off and on the phone it result in a change of active sim.
2) typing #3370# result in a SIM carda interchange for nokia series without turn off and on the phone.

No sim change apply on my 6600.

Someone can help me with some suggestion?
TKS

dual sim card work on older model of nokia 3310,3390,6610 ect...
but im not sure about 6600. try *3370# to see if the phone will react.