It mounts them for me on Current and on 14.0 before I moved to Current. More information might help.
What is the output of lsusb in a termial before you insert the USB device and afterwards?
You might also try running dmesg in a terminal and checking whether and how the device is being seen.
If you post output of those commands, be sure to surround it with "code" tags, which become available when you click the "Go Advanced" button at the bottom of the quick reply window.