I have a 3g on 3.1.2. It relies on a hacktivate so I can't take it to 3.1.3 because I can't ever get past the 1600 error when restoring via iTunes (sn0wbreeze modified 3.1.3), even with iReb - it never gets the white/red screen.
So I finally just left it on 3.1.2. redsn0w works but Cydia is always FUBAR in the install.
So I managed to get 3.1.2, blackra1n to get it hacktivated and then ran jailbreakme.com to fix issue + remove tether. Now it runs fine, unlocked fine BUT............ Cydia is crap.
It worked for 3 times, now it gets stuck at "Loading Data" and crashesh.
I have remvoed the apt/lists contents multiple times, reboot -> it redownloads data and goes right back to the issue.