Searching Signal few hours after jailbreak IOS 6.1

[superman3456]

HI

This is the first time I jailbreak / post here. I jailbreak an iphone 5, IOS 6.1 sprint using evasion. Everything worked perfectly but after few hours of being jailbreaked the phone keeps searching signal. The only way to fix this is recovering the phone via Itunes. I have made the same process 3 times! Does there is any fix to this?

Thanks!