I've just got round to putting together a Gringo (2001 or so model) for a mate, and the rear drop out spacing is massive - 10mm or so wider than a 135mm hub.
You can give them a bit of a squeeze and fit the wheel fine, but it's a bit of a faff. Is this an attempt by Orange to make sure the back wheel stays in if your QR comes undone or what? It's an alloy frame so it's not likely to have been respaced. I also doubt it's been built for big DH hubs given it's a hardtail that originally came with an Alivio group and WTB XC wheels.