Is this the dreaded Leica Sensor problem?
You don't say which Leica you are using, so I will assume it is the M9.
I think there has only been one significant 'Leica sensor problem' where a very few early M9 cameras developed a crack in the corner of the sensor. There has been the odd faulty sensor, but the vast majority of problems have been caused by the M9's low tolerance of poor SD cards, or even people not keeping a good card healthy (like using it in different cameras without reformatting it etc). While a cheaper card can work perfectly in other cameras something about the M9 doesn't like them. But your images fall into the 'card' category as far as I can tell. Do a belt and braces job, new card, format, new firmware if not done already, reset camera defaults, format again, and good luck.
I use SanDisk Extreme cards and they have worked perfectly.
Steve