I did a search on this issue and was only able to find one person with this problem (but no responses or solution). Occasionally I'll glance at my e71 and see that I have no signal in an area where the strength should be strong. The only way for me to get the network back is to reboot the phone or switch to offline mode and then back. When I do this the signal returns at full strength immediately. This seems to happen when I pass through an area with no signal and then back to an area with a signal. For some reason the phone never picks the signal back up. It happens when I have the phone on dual mode as well as GSM only.
The problem of course is that I never know for how long I've been without signal or how many calls I've missed. The only way to know when it happens is either to glance at the phone by chance or to try and make a call. I'm on Orange Dominicana (but I don't think its a provider issue). Is this a known issue that perhaps a firmware upgrade will reslove? I love this phone but this problem renders it practically useless for me. Thanks.