Mirf examples not compiling.

I'm having trouble getting anywhere with the Mirf library. I'm unable to even compile any of the example codes that come with the library. I consistently get this error message:

'Mirf' was not declared in this scope

I have tried with 2 different versions of Arduino IDE, 1.6.5 and 1.0.6
I have spent many days trying to find the solution but have had no luck at all.
A friend suggested removing all other libraries in case of a clash but I still the same error after trying that.

I also tried it with the rf24master library installed and that didn't help.
This is where I downloaded the Mirf library from:

I'm running Windows 8 64bit in case that's relevant.

Any help would be great as I'm all out of ideas.

I just downloaded the library: https://github.com/aaronds/arduino-nrf24l01/archive/master.zip
Unpacked the .zip file.
Moved the Mirf folder to my libraries folder.
Re-started the IDE (1.6.5rc3).
Selected File->Examples->Mirf->ping_server
Selected Tools->Board->Ardiuno UNO
Clicked on the Verify button.

It compiled without error.

How does what I did differ from what you did?