i do this
1# restore on 3.1.2 it said error 1603
2#download ireb .......nothing
3#download tinyumbrela ...the key for kick off doesn't flash
heeeeeelp

Forget iREB - it is not something we recommend.

Publish your restore logs: http://www.hackint0sh.org/f137/130802.htm
My guess is that you have a problem with your iTunes install.
Error 1603 When Restoring iPhone in iTunes

TinyUmbrella will only kick you out of recovery when the restore failed with an unable to downgrade baseband error.

•iTunes version (e.g.1.0.1.2.17
•iPhone OS version (before restore/don'know)but i try and finally succeed with redsn0w-win_0.9.4 and iPhone1,1_3.1.3_7E18_Restore
•Platform (e.g. OS X, Windows, Windows x64 vista
restore Log one of them
2011-01-20 21:34:33.951 [3300:17fc]: restore libra - Log of iphone 2g

this is my last log and i do everything like they say on this Error 1603 When Restoring iPhone in iTunes
and same thing again
2011-02-12 10:16:19.237 [2952:788]: restore librar - Log of iphone 2g

Try a different computer