oh ohhhh...
Doesn't look good. Got my 512M Viking CFC today, plugged it in (loved it when my screen said I had 95 minutes of recording to go), threw a minute's worth of stuff on each of four tracks, then bounced to 5/6. The card is choking. The MR-8 acts like it's bouncing, but there are no tracks on 5/6 when it's done. Also, as the unit is "bouncing," I get some weird digital artifacts (sounds like the signal is clipping randomly from track to track) in my headphones. I already tested it with the original 128M CFC, and bouncing works fine on my unit, so it's gotta be the Viking card that's the problem.
I'm going to perform further testing tonight, but it looks like the Transcend 512M may be the best bet for now. If I can't get this Viking to work by tomorrow, it's going back to Amazon, and I'm gonna order the Transcend from My Digital Discount.