Nokia :: 2700 Loss Network Connection

On the new phone Nokia 2700 classic (after official upgrade to firmware ver. 09.95) periodically disappears icon of a signal of a network, after a while phone show the message "Error of registration of a sim card" and an inscription "there is no service" on the screen. After disappearance of the indicator of a network it is impossible to make a call and to fulfil USSD-inquiry, while on other phone (other brand) with a SIM-card of the same operator the network works absolutely normally. The network appears only after device reboot, hand-held search of a network does not help even. Network miss is often observed at attempt to be connected to EDGE, also the signal can disappear and itself, without what or my operations, in a standby mode. Replacement of a SIM-card has not given any result. Phone works in a range 1800 MHz.