I purchased a Sonnet Dio CompactFlash and SD card reader a few years ago to read the CF cards from the Nikon D800. While I still use the D800 on occasion, I mostly shoot with the newer D750, which used two SD cards instead of the CF/SD combination. One advantage of the D750 is that I can just pop the SD card directly into the MacBook Pro to import my photos, so I haven’t used the Sonnet Dio as much as of late.
When I recently tried to use the Sonnet Dio, I encountered a connection issue where the card kept getting disconnected. Not the safe disconnect, but the one that prompts a warning. At first, I thought the reader was somehow failing. However, this morning, I thought that the USB cable may be the culprit. So, I swapped cables and the connection problem disappeared. Glad I was able to figure this one out.