Yes there are problems in some dual sim mobile phones, I am also using a dual sim nokia phone, so the problem is If I get a call from one sim then during that call my other sim will be off. so what is the benefit for this dual sim ?
It is a common problem in all Dual Sim phones. Dual Sim phones connect with two networks at a time but you can make or receive calls through one network only as the other sim network goes into a busy mode. In normal cell phones you cannot attend two different calls at a time. Like that dual Sim phones are designed in a way that when you are using one network the other network is made idle or busy. But you can browse the internet using one network and call using other network simultaneously. Another issue is when you make a call or receive calls through both networks simultaneously; your phone tends to overheat which may reduce the life of your mobile. It may even put human health in danger.