Kirk,
I have a Delkin Devices card reader. Hi-Speed USB 2.0, DDREADER-38. I haven't had any problems with PM with a D3 it just seems to be the D300s.
Yes, if I Ingest using the Finder I get the same error.
Work current work around is to just copy the images to the desktop folder, THEN go into PM to make my selects, caption, etc. I edit in LR3 from PM. It's just the ingest that seems to be the hiccup.
Tim