I would recommend getting a replacement. Pots never get any better when they start going bad, and flickering on the center area is usually the first sign of things starting to fall apart. Followed by spiking, lacking feedback area on some ends of the axes, and so on. Just go in the shop and say that one axis is off-centered and flickers around the deadzone and you'll likely have no problem getting it replaced.
Of course, with the Cyborg Evo there is the chance that it's simply a mechanically non-centered (or possibly slightly loose) sensor, in which case you *can* go inside the stick and slightly tilt the offending sensor so that when the spring centers the stick, the sensor is also centered. Of course, if you do this you can pretty mch kiss goodbye to warranty (technically anyway, you can always try to deny you did anything...).
My stick does has somethign like this going on, the roll axis indicator is slightly off-center but it doesn't really flicker or spike, and reaches both ends of the scale... so it's just a mechanical fluke in my case. But the flickering kinda sounds bad to be honest on your stick.
Also, I've noticed that a couple drops of some kind of oil (or silicon) in the spring gimbal system, especially between the plastic sleeve and the stick, tend to prevent wear and tear that eventually increases the mechanical deadzone of the stick. But for now, just go and get that replacement stick.