The thread title isn't AT ALL fair. Patch Z does NOT = no G25 for everyone.. "WARNING" scaremongery is not in the slightest helpful. I'll be editing that out in a moment.
I have found that the Logitech power pack has "memory" sometimes. I've found, occasionally, that no matter what I do with drivers and reinstallation/reboot, until you unplug the Logitech power pack for 30 seconds *FROM THE WALL* and plug it back in, my wheel will not do anything it's supposed to do. Turns out I'm not the only one to experience that at all. Give that a spin.