Multiple D-pad bindings causing problems with Xbox 360 controller

[Finzy]

I've been trying to set multiple bindings for D-pad on the Xbox 360 controller, so I can control the PSP D-pad with both the Xbox360 d-pad and the right analog stick at the same time.

Now using the right analog stick to control the D-pad works just fine, but for some reason, if I also have it bound to the Xbox360's d-pad at the same time, it causes the d-pad controls to become very unresponsive, like I have to mash the d-pad buttons multiple times for anything to happen (and often they just don't work at all), while the right analog stick controls still work fine.

The reason I'd like to have multiple d-pad binds is that many games use the d-pad for controlling the camera and I'd love to use the right analog stick for that when I have one, while still retaining the ability to use the d-pad in menus and such.

Any idea what causes this, or is it a bug? (I'm using Windows 7 64 bit, on the latest official 0.9.6 build of ppsspp)

EDIT: Forgot to mention, this happens in all games, so it's not game specific.