I have the original stereo SACD of Rebecca Pidgeon [i]The Raven[/i]. The catalog number is SACD205. I just recently learned that there is also a multi-channel SACD, catalog number SACD329. Do the two discs have the same stereo SACD mastering?
I would look to see what labels they are under and who did the mastering on both. That should give you more of an idea. Also look at the time between each of their releases. Closer together would give more a chance.