Downgrade bb 5.15.04 BACK to 4.26.08?

[freemotion]

Hi,

After dropping dev team's 4.2.1 bundle into pwnagetool 4.1.3 and creating a custom ipsw, i then got my 3GS (old bootrom, week 25) into DFU mode and restored with the custom created 4.2.1 ipsw.

Worked fine.

Then, I used latest redsnow (0.906rc8) to jailbreak.

Everything seemed fine, except when I went into cydia to unlock, and the phone when to the black
screen with the apple logo and the spinning wheel that would chrip/buzz (depending if I had the sound on or not) every 5 seconds.

I finally got it back into DFU mode, but pressing home & power for 10 seconds and then just home for 10 seconds.

At that point, I went into iTunes and accidentally chose to restore using not the custom 4.2.1 but the "Restore" 4.2.1.

It was then I noticed that my firmware/baseband was upgraded to 5.15.04 and it was not at 4.26.08

Is there anyway to get back to 4.26.08?

Cydia has all my SHSH upto 4.2.1 (although I don't know how to get them and use them - but I'm a good learner).

Anyone know what I can do?

Thanks.....

Many thanks.......

[iYeow]

You have restored to stock 4.2.1 that updates your baseband. It is irreversible.
You have to go with ipad bb if you want to unlock. Run redsn0w and choose ipad bb update.