Ok first i also experienced it , i buy new ipad in first day , my ipad in ios 4.2.1 . And i jailbreak it , until one day , ios 4.3 release , i upgrade my ios to 4.3 , ( forget save shsh) , then i cant downgrade anyway , when snowbreeze relase jailbreak 4.3 , im just jailbreak my ipad 4.3 , ...