Hi, My issue is: I purchased a brand new Samsung Galaxy Ace S5830 on 14-Apr-2011. I am facing the issue related to the connection to my phone network. After I switch on the phone, I get my mobile network signal for about 30 minutes and after that the "No Service" icon is enabled and there is no signal at all in my phone. I checked the SIM card on a difference phone and there is abosolutely no issue in getting the network signal. I tried a different service provider SIM on Samsung Galaxy Ace S5830 and I find there is no issue either. The problem seems to occur only with my SIM card on this phone. I changed to a new SIM and apparently that also did not solve the issue. I am also unable to find the "Network Mode" option under the network settings, which I would normally find in other phones. I tried with the option "Use only 2G network" but that also did not help. I am not using any 3G service at the moment. I am now stuck in this situation and not able to use my new phone. I am from Chennai, India and use Vodafine India post paid service. Hence seeking your kind advice to help me resolve this issue at the earlier. Thanks and Regards, Venakatraman R.