Hi,

I've been researching on the net a while and alas, I'm confused. I'm hoping someone here can help me out. The pdf in the sticky is helpful but may be out of date as there has been a lot of greenpois0n activity in the last few days, so I'm asking here...

1. Can I upgrade from a blackrain jailbroken 3.1.2 to 4.2.1? From Guru Guide: How to Jailbreak your iOS 4.2.1 iPhone 4, iPhone 3GS, iPod touch and iPad Untethered Using GreenPois0n on a Windows PC | The iPhone Guru it seems as though I can't as it says I can't if my iphone is unlocked as there is no carrier unlock for 4.2.1.

2. So if I can't, what should I be looking out for that's expected in the near future that will let me upgrade my jailbreak?

3. On the other hand if I can, can jailbreaking lose your data? I need to keep my SMS data for legal reasons, so need to be sure that I won't lose it.

My details:

I have an iphone 3GS jailbroken with blackrain (Version 3.1.2 (7D11); Carrier 5.0; Modem Firmware 05.11.07). I don't know if it's new or old bootrom, but as I got it from O2 in January 2010 it's probably new bootrom. It was officially unlocked by O2 and I'm now on T-Mobile. I have everything but the apps synced to iTunes 9.1.0.97 on Windows 7 Professional 64-bit.

Thank you for the help!