Iphone 3gs 4.2.1 jailbreak

[Chinks1234]

Hi Everyone

I did jailbreak activity successfully through REDSNOW 0.9.6b5. Baseband was also updated to 6.15 but the Cydia was not working!

Every time I press Cydia it keeps on pop up only and goes to menu screen of iphone only over and over again ( every time I do it )

I tried to restore it with iTunes, it went to recovery mode. I am not able to restore it with iTunes as DEV TEAM also mentioned in his blog "Starting with FW 4.2.1 if you have 06.15 on your iPhone you won’t ever be able to restore to stock firmware (it will fail). You’ll need to only restore to custom IPSWs."

Any advise for me to do on this problem?
I know that It cannot be use the original IPSW from apple since it is already jailbroken from redsnow.

My Iphone is in recovery mode. Please tell me how to get out from recovery mode and jailbreak it.

Please let me know how to restore it with custom IPSWs.

Please please help me...... I got stuck..... Never did this before..... Please help me....