I suspect the additional device is due to the recent addition of MTP support to FCXE, but it really shouldn't be doing this for a simple USB card reader, as it isn't really an MTP device. Windows Explorer only shows the reader as a removable-media drive, not as a camera.
If I expand the tree or double-click the "camera" icon, it shows a "removable-media drive" icon within the "camera" folder, with a "name" matching the same drive letter as the separate device for the SD card reader (in this case, "K:"). This "removable-media drive" is shown as type "DCF" in the files panel. And within the "drive" are all the files and folders that exist on the SD card itself.
I noticed that listing the card's contents (when there are a lot of files) takes far longer when accessing it as the "Camera" device than it does when accessing it as the basic "removable media" device. Also, if I were to, say, select a JPEG file on the card and try to view it with the FCXE Quick Viewer, I get an error message with a long string of gobbledygook, along with "Cannot open file, the system cannot find the path specified." I click Okay, and get another error "File not found: "::\"".
I can select files and copy them off the card to another drive, but there is no progress dialog like with a regular file copy, just a "busy pointer" until the operation is finished.
See below for a screen shot:
Aimhere