It's not just you. I get annoyed when I even see Spuffy manips that I know are using B/A photos, or vice versa. I think it's because I'm so much more of a canon person than much of fandom. If I can't find enough to support my ship in canon, then I wouldn't ship them in the first place, you know? I can sort of see doing this if you're doing a total AU with a couple who frankly don't have much of anything in canon to use? But I always feel like swapping B/S, B/R, B/A scenes around is CHEATING. Hee. C'mon, all three have plenty of their own material to use.