I just found Crucial 070H for the M4.
Release Date: 04/12/2013
[B]Firmware 070H is recommended for anyone currently running 040H[/B] or previous firmware releases. It includes incremental improvements and refinements over these versions which may improve the overall user experience.
Like recent firmware versions, version 070H has improvements over versions 000F which are specific for Windows 8 and new UltraBook systems, although systems running Windows 7 and other operating systems may also see improvements. Any m4 firmware version will function normally in Windows 8, even without these performance improvements.
The following is a summary of changes between 040H and 070H, which are independent of operating system:
[li]Resolved a power-up timing issue that could result in a drive hang, resulting in an inability to communicate with the host computer. The hang condition would typically occur during power-up or resume from Sleep or Hibernate. Most often, a new power cycle will clear the condition and allow normal operations to continue. The failure mode has only been observed in factory test. The failure mode is believed to have been contained to the factory. This fix is being implemented for all new builds, for all form factors, as a precautionary measure. The fix may be implemented in the field, as desired, to prevent occurrence of this boot-time failure. To date, no known field returns have been shown to be related to this issue. A failure of this type would typically be recoverable by a system reset.[/li][/ul]http://www.crucial.com/support/firmware.aspx