Download HIDTest, copy your controller.ini to the sd (if that's where your apps folder is); and then load HIDTest to check if your R button is being detected when pressed. if it doesn't change to 1, it might be badly configured.. it should also show which offset and value change when you press it, so you can compare with your ini and fix it if needed.
He did mention using two controllers, so it must be either that or tests for a certain kind of adapter. I'd guess that for Multi-HID it would make more sense to ask people with usb HUBs and more than one usb controller instead of a ps2 controller.
It'd be cool to find a way to use hubs to connect more than one controller in the same port (specially for the wii family edition), but i'm not sure if that's easier than getting bluetooth to work, or if it's possible at all.