iPhone 3gs 8gb 4.3.5 downgrade to 4.1 then jailbreak & unlock (3pcs)

I've successfully downgrade iPhone 3GS 3pcs 4.3.5 thetered to 4.1 unthetered smooth, here are a small guide you must follow to go back 4.1 version w/out shsh blob's saved.

Guide:

• check the boot using serial checker by chevli if it is old or new (follow this steps to avoid brick)
• cut hosts file to desktop 
• put iDevice to DFU mode using any dfu mode forcer
• open itunes and restore to firmware 4.1 (official)
• now if the error occur like 1015 (just loop using ireb or tiny umbrella)
• jailbreak using jailbroken tool made by white's using redsn0w_win_0.9.6b6 (fetch ipad baseband w/ out net connection)
• then if the jailbreaking is succeed, sync ultrasnow & appsync no wifi using ifunbox
• that's all folk's, cheer's. . .

I have successfull downgraded & updated the baseband of 1 phone, but the other two there's a small bit problem occur during restoring & jailbreaking. Now i wonder why? And thinking for the alternative solution's, Here it is;

Problem:

* during restore an error occur 1015 (recovery mode)
* loop recovery using ireb again (another stuck on recovery mode)
* i decided to force jailbreak using redsnow but suddenly fail

Solution:

* restore again the device in itunes
* recovery loop too again using ireb looper
* then if the device is on emergency mode now
* jailbreak again using jailbroken tool by white's
* that's all tips.