EDGE/GPRS goes offline

[addy]

Hi,

I just bought an iPhone 3G v 2.1 and unlocked it through a turbo sim. I am facing a problem that after every 3-4 hours the EDGE/GPRS sign at the right of the carrier signal disappears & I am unable to use EDGE/GPRS on my phone then.

I have to reboot the device to get the EDGE/GPRS sign back and then an able to browse. I dont neither have 3G in my country nor wifi, so EDGE/GPRS is the only way to browse. Does any one has a solution for this. Is there any application or trick that could bring the EDGE/GPRS sign back again & get it working or any other solution for this ?

Please help!! Thanks.