Greenpoison 4.2.1 Jailbreak

[shanafan]

I currently have an unlocked 4.1 3GS running on T-Mobile network, with 5.13.04 baseband.

To keep my unlock intact, can I proceed with the newly released 4.2.1 jailbreak by Greenpoison, or do I have to wait?

I remember I had to run SAM to activate my SIM card when I did the 4.1 jailbreak.

Thanks!

[shanafan]

Bump.