Interesting you should mention this. Not long ago, I was watching my DS DVDs and I experienced the same thing, but wasn't sure if I merely imagined it/was flashing back to 1983 and its run on NJN. I'll have to go back and check out that episode.
On a related note, I forget the exact episode, but in one of the pre-Barnabas episodes there appears a very faint image of what appears to be a person during the fade out/fade in between two of the acts. I know that commercials were fed directly into the episodes during taping, so I'm guessing that a frame or two of a commercial was accidentally left in this episode when the commercials were edited out for home video. (Part of me wishes that MPI released the entire series with all of the commercials intact...)