I had no problem whatsoever PMing @ Target (one by Millenia Mall in Orlando) with the GC. I did this last Sunday, saw a lot of confirmation posts also, so I didn't bother to add. However, since it seems more hit and miss since then, decided I would post my success so others could see it is happening perhaps moreso than is being reported.
I had the electronics employee bring it to CS, where I presented the BB ad. I did not mention the GC. They rang it up, PMed it and then rang up the GC (because they are prompted to do so) with no questions asked. I paid with my Target card to knock it down a little more and it was over. Pretty painless.