First I would ask if there is a big chunk of metal, the computer case, directly between the dongle and the device you are trying to pair? That dongle works great, but it's antennae and resulting range is poor. I would get an extender, or plug it in a port that allows it to be on the same side of the case as the devices you are typing to use.
I would suggest using a usb 2.0 port, and installing the universal 3.0 driver can help sometimes, I had to replug the module boot to get it to actually work until I installed the 3.0 driver, and yes it was plugged in to a usb 2.0 port.
I've had to delete the com.apple.bluetooth.plist after moving bluetooth modules around to get Mavericks to use the same module in a different port.
These tips are from the bluetooth experience on 2 different hacks, the former on a intel motherboard with recommended dongle, and the latter on a Gigabyte board and genuine Apple internal module.
