Apple has released iOS 6.1.2 to fix a bug with Microsoft Exchange Calendar.
Fixes an Exchange calendar bug that could result in increased network activity and reduced battery life.
For those of who want to jailbreak use Evasi0n 1.4 Released With Support for Jailbreaking iOS 6.1.2
Evasi0n 1.4 (Mac)
Evasi0n 1.4 (Linux)