Everyone:
This is my first post here. I've lurked since Skyrim came out, but I never felt the need to post because any questions I had were answered in the forums. But after what I discovered just an hour ago or so, I felt the need to register an account so I could warn my fellow PS3 users about this:
DO NOT "discover" Castle Volikhar *before* you rescue Serana from Dimhollow Crypt and bring her to the castle. If you do so, the Dawnguard DLC will not — I repeat, WILL NOT — work. Serana's dialogue never activates at the castle (where she wants the player to behave him/herself at let her do the talking), and the castle watchman simple repeats over and over that the player isn't wanted there, and that trespassers will not be tolerated.
I found this out the hard way on a character I had invested 64 hours in. Unfortunately, I had no earlier saves from *before* I "discovered" the castle, so I'm pretty much screwed with the character and will be deleting it shortly. I even tried reloading an earlier save, but there's no undoing the bug if any of the saves take place after the "discovery" of Castle Volikhar.
Fortunately, I have two other characters who can access the Dawnguard DLC. But they were pre-existing characters from before the DLC was available. The third character was a new one, and I had high hopes for it. Now, those hopes are dust, and I'm going to bed.