[rick5505]

Originally Posted by sysek

hm.
1. put iPhone on DFU mode (YouTube - How To: iPhone DFU Mode - MacComm.tv)
2. open iTunes
3. you will recive message, that your iphone is in recovery mode
4. shift + restore, pick 4.1 fw (you can download from here Download iOS Firmware)
5. wait for restore, then will be error 1015
6. your iPhone will in Recovery Mode, download Tinyumbrella (The Firmware Umbrella - TinyUmbrella) and kick out from recovery mode.
7. Then put again to DFU mode, restore with 4.2.1 and you have.

now i'm doing that

This does not work for me. I am on 3gs with updated BB 6.1.5.
I cannot get it to 4.2.1. I am stuck (but working and untethered) on 4.1.

Would really like to get back to 4.2.1, since that is where by only backup is at.

Regards,
Rick