I've never yet had a camera or lens that doesn't show it. That includes Nikon, Canon, Leica, m4/3 - everything. Worst of all was my original Canon 5D, closely followed by the Nikon D3X. Full frame sensors do seem more prone to this. The Leica is reasonably good, especially for a sensor with no AA filter. Its fixable, but it takes time.
The curse of the winter landscape photographer.