iphone 4 could not be activated due to unknown error. 0xE8000004.

iphone 4 could not be activated due to unknown error. 0xE8000004.

Since i upgraded myself to iphone 5s, i decided to give away my iphone 4. So i started by erasing all contents and settings from iphone 4. It automatically reset the settings. But when i tried to turn on the phone and sync it with the itunes, i get a message saying - iphone could not be activated due to an unknown error numbered - 0xE8000004.

i have read posts which ask me to downgrade the ios... Is this the only solution or is there a simpler one?

Some one from Apple - Can you pls fix this bug?