I own both and it is still not working, i have heard everything there is to hear about this situation accept someone confirming that in fact the buying the HDD does make the system backwards compatible. I don't want someone who just says that it works. I want someone to confirm this! I want someone who went to a gamestop or something like it went home put the HDD in the 4gb slim and played a original xbox game that was not able to work before the HDD.
This information honestly is needed terribly becuase no one i've talked to has given me that answer thus far.