I just bought the blu ray combo pack last night. I got the error that it was an invalid code for the digital copy. I entered it many time, using CAPS and no-caps. I went to the WB support link that was listed earlier. But it didn't allow me to submit the information. I tried in both the latest versions of Safari and Firefox with no luck. I also tried with the latest and 2nd latest versions of iTunes on OSX. It gave the same error regardless of which version of iTunes I used.
BTW, the WB website form is horribly out of date. It lists the iTunes version as ~7. Yes you read that correct, version 7, not 9.
Any solution for the 'invalid code' ????