Yamaha RX-V2500 - Possible to use another power cord with it?

[Greekguy]

Hey everyone, quick question... The Yamaha RX-V2500 uses a detachable power cord, and I want to upgrade from the crappy one it ships with... I got a Merlin Black Widow which fits the socket just fine, but there's only 2 leads coming from the socket end of the receiver, and the Black Widow has holes for 3 leads, it looks like this (omit the dashes, look at the |'s):

-------------------------------------------------|
Receiver: |---------| Power Cord: |---------|

I wonder how safe it is to use another power cable with the Yamaha, the manufacturer of course says it poses a fire / shock hazard, but I don't see how using a $250 power cord can be dangerous compared to using the cheap dollar store one that ships with the RX-V2500.

If anyone has done this and can let me know safe it is, I'd really apreciated it. My main concern is the extra hole on the power cord and the one less power lead on the receiver.... thanks!