Should i do this ?Simply plug your iPhone in, back up in iTunes, then hold power & home for 10 seconds, then release the power button but keep holding home until your computer detects the phone, open iTunes, and click restore. It'll then upgrade to 5.1.1, then you can restore your contacts, apps, and music back onto the phone. After that, it's always best to click Reset All Settings (won't delete apps, music, or photos, just reset the settings on your device, which is good to get rid of all jailbreak files), then use Absinthe 2.0.x, or the latest redsn0w. And, just some advice, but you should update more often, better for the device.