The Leica M9 & M9-P have a firmware update (version 1.176) that solves a SD card compatibility issue.
This update from Leica should be installed by any photographer with an M9, M9-P or M9-T. The new firmware version will have an overall impact to how your camera functions and the photos it produces.
We can also update your cameras software for free as part of the cleaning and repair services. If you cannot get to NYC or just want to update your camera, then the link below will take you to the firmware pages.
Note – Make sure you use a good, formatted card to upload the update. You must also make sure to use a full charged battery. Some of your user settings will be lost, so make a note of any thing important. You should also take a note of the last file/image number.
From the Leica website -
Modifications enabled with this firmware upgrade.Firmware update 1.176 eliminates a rare fault occurring during the formatting of SanDisk cards, ensuring compatibility with the Leica M9 and M9-P in accordance with the cameras’ respective standards. All card types available from SanDisk have been fully tested by Leica’s expert technical team and firmware version 1.176 guarantees their proper function, resulting in the previous constrictions on the cards being revoked.
For a clear and full explanation of what the software/firmware update click on the button below. You will be taken to the correct Leica download page. From there download for Mac or PC and follow the online instructions.