Yep. you raced ahead "a bit"... you have to do the prefs: thing in 1.1.1. It won't work in 1.1.2. So you have to downgrade using iTunes (again with a +150 MB 1.1.1 .ipsw file), iTunes will give you an error cause it can't downgrade the baseband.
Then you do the prefs: thing, install oktoprep, upgrade to 1.1.2 and re-unlock (if necessary. i have the feeling you are unlocked)
I'll check bak later. please tell me how it goes.