Did that....right away earlier in the week. I couldn't circumvent the DFU iTunes firmware update to iOS 8 without backing out of DFU mode. I had already saved the backup .ipsw knowing that I would need it so I knew I had the correct version. I was so pissed, but fortunately I did the restore earlier today (not in DFU) mode and it worked. Hopefully there is no difference between the DFU install and the Restore (holding down SHIFT key while pressing RESTORE) because the Pangu jailbreak left my i5 unstable. However, come to think of it, I don't believe I was presented the option to install the .ipsw file while in DFU mode. Maybe I didn't hit SHIFT restore in DFU mode?
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Nope, that didn't work for me (see above post)to Cyber16.