I have seen FCs with the debinged ED01 and trying to use the EC01 radio. It kept acting up for about 5 days and I finally got fed up and got the ED01 modem.
It was shockingly easy if you are familiar with odin and CWM. Just run a backup, flash the DJ05 rom via odin, then boot the phone up and wait for it to star harping on you to update. The EA28 update is fast, the ED01 update is slow (its 100mb). Once the ED01 update is finished, just restore your backed up rom and you are back to normal with the ED01 radio.
I found that it cleared up my FC issues (unless it was the habitual cache clear i did after reloading the backup) but battery life is still pretty dismal.