not sure if this is related to your issue.....but i was jailbreaking a 3GS 4.1 with redsn0w yesterday Dec 23/2011 and everytime i tried to lauch cydia to install and unlock the phone, i got errors and it would not install pkg's ??? tried numerous times??? would the cydia server be down??? anyways...may not be your issue but i have never had issue when it came to lauching cydia to install files and use ultra snow to unlock.....but yesterday cydia would not work for me.....so i will wait a few days and try again...