Use the Pickit 3 beta program and under Tools menu choose to "revert to MPLab mode" . it will go through a few process and reload your Pickit 3 back to its original state.
After that process is done, connect to the device (ether dongle) open up the MPLab IDE program
Under the configure menu choose "select device" and set the device to the PIC32MX795F512L. and click OK.
Select Pickit 3 from the 'Programmer" menu , and it will tell you that your pickit 3 needs to be updated. It will then load the pic32 device onto your pickit 3.
After that process close MPLab and open Picit3 ver 1.0 software (available in WIKI) and you should now be able to select the correct 32pic device and load your ether dongle hex firmware and program your ether dongle.
I am posting this from memory. but I believe i have included all the steps. It might ask you to load the pickit 3 firmware, i'm not sure. But the firmware is loaded through the MPLab, Programmer, setting, configuration menu, and the firmware is located in the PICKit 3 folder.
I'll confirm this procedure in the morning when I am at my programming PC with my pickit 3 device.
kevin