That is pretty much what I did. the only difference is that the library folder is inside my sketchbook\libraries folder, so it is visible across all the IDEs I use.
This is what I get when I try to compile that very same sketch:
USBHIDJoystick.pde: At global scope:
USBHIDJoystick:22: error: redefinition of 'USB Usb'
USBHIDJoystick:22: error: 'USB Usb' previously declared here
USBHIDJoystick:23: error: redefinition of 'USBHub Hub'
USBHIDJoystick:23: error: 'USBHub Hub' previously declared here
USBHIDJoystick:24: error: redefinition of 'HIDUniversal Hid'
USBHIDJoystick:24: error: 'HIDUniversal Hid' previously declared here
USBHIDJoystick:25: error: redefinition of 'JoystickEvents JoyEvents'
USBHIDJoystick:25: error: 'JoystickEvents JoyEvents' previously declared here
USBHIDJoystick:26: error: redefinition of 'JoystickReportParser Joy'
USBHIDJoystick:26: error: 'JoystickReportParser Joy' previously declared here
USBHIDJoystick.pde: In function 'void setup()':
USBHIDJoystick:28: error: redefinition of 'void setup()'
USBHIDJoystick:28: error: 'void setup()' previously defined here
USBHIDJoystick.pde:39: warning: only initialized variables can be placed into program memory area
USBHIDJoystick.pde: In function 'void loop()':
USBHIDJoystick:42: error: redefinition of 'void loop()'
USBHIDJoystick:42: error: 'void loop()' previously defined here
I know some of those messages make absolutely no sense.
I've made sure there are no other USB-like libraries in use.
Also, I've tried the above in 2 IDEs, with the same unsuccessful results: Arduino 1.0.3 and ERW 1.0.3