Area151,
Not sure why this happened to the EEprom maybe the bios you used to flash Tsop (4979) might be causing corruption? it's funny that we used same bios and same problem occurred anyway since i recovered it, the EEprom failed again but seems to be fine this time for now. I will try to flash with 4981 tonight to see if that helps.
I did this using the Xenium chip but if you have configmagic final you can use this to do a blind restore of your EEprom. (Configmagic can be found in the usual places) ...

You need a copy of a good EEprom backup, created by running backup in Configmagic or possibly Evox dash on a working modded xbox. (I believe if you use someone else's eeprom ensure that you both don't use Xbox Live or you will be banned).
you then have to copy configmagic files onto a cdr/rw or dvd whatever your xbox reads.
ensure you copy the backed up EEprom files to the Data dir and ensure they are renamed to eeprom.bin and eeprom.cfg once you have your cd/dvd burned follow step 2. below....
Taken from Configmagic final readme.txt courtesy of Team Assembly.
"1. You can update your XBOX EEPROM in one of four ways
* using a valid EEPROM.BIN file
* You can "build" a new eeprom image from a configuration file
* Edit your current, loaded (.bin) or built (.cfg) eeprom data "On-The-Fly"
* use our BLIND restore feature to restore a .bin file if you have no visuals..
2. Blind Restore EEPROM if you have no Video image..
Usage: (MAKE SURE YOU HAVE A VALID EEPROM.BIN in \DATA)
1) Boot ConfigMagic from DVD Drive
2) Press A button to Skip Video (press A untill you see the orange light flash)
3) Wait untill eject light flashes orange (flashing orange means ConfigMagic is ready)
4) To Start Hold BOTH triggers and press WHITE button !
5) Orange light stops flashing and stays steady (Steady orange means busy)
6) If successfull Eject light will Flash GREEN (Flash Green means success!)
*IF there was a problem loading/decrypting eeprom, Eject light will turn RED (Red means Error !)"
Good Luck!
I hope this helps...