Third Test is a "charm"..... but why? I deleted all the files and folders from the OTG. I copied a different set of NEF and JPG files (310 files, 957MB) onto the CF card. I attached the reader to the OTG. The OTG had over 40GB of files on it, and is supposed to be able to handle this. It's capacity is 80GB. It is formatted as FAT32. NTFS won't allow it's firmware to to do the copying function. The copying was finished in 2min:50sec - that's about 3 minutes for a gig, which matches what others have done - 6min for 2GB. I'll recontact Tech Support to see if they have any ideas.