Getting a weird error when restoring my Iphone 4

[ipod touch u]

Whats up guys, i recently jailbroke my iphone 4 on 4.2.1 using the teathered jailbreak. and now i am going to be jailbreaking it with the greenpoison unteathered jailbreak. When i try to do a fresh restore of the phone, i get an error that says " The iphone could not be restored. This device is not eligible for the requested build". I have never heard of this error and would appreciate some help

EDIT: now i tried on a pc instead of a mac, and itunes is stuck in the "verifying iphone restore with apple" stage of the restore, and hasnt done anything in 30 mins


Thanks.

[i.Annie]

You might be using the wrong firmware. If you're updating with iTunes and not shift+restoring, try another computer.

[ipod touch u]

You might be using the wrong firmware. If you're updating with iTunes and not shift+restoring, try another computer.

i was using a mac before, now ill be trying it on a pc and see if that works.

Anyone else got some advice

[i.Annie]

Well you never confirmed whether you checked to see if the firmware version used was the right one for your device or not, nor did you say if you were shift/option+restoring or just hitting upgrade in iTunes. It's hard to really give exact advice without exact details.