I don't believe it's that version of corruption, I have dealt with that before. There are other gradients and patterns in the file which also have similar names, but I don't see any of the issues with brushes or symbols which I have seen with files that are corrupted in that way.
I am currently trying to determine where this document came from. It is possible that it was from a clip art or other similar file originally that was edited locally, but I haven't been able to verify this. I believe if I copy the contents to a new document, the resulting file has the proper registration color, but I am concerned if there is anything else that is being copied with the art (and possibly corrupting the new document).