If you have a Crucial M4 SSD, you will definitely want to install this firmware update. Instructions on how to "burn" the ISO to a USB flash drive can be found here.

Revision Firmware 0309 is now available. This firmware resolves the issue where a m4 SSD required restarts after approximately 5,000 hours of actual "on time" use.

If you are using a SAS Expander please do not download this Firmware. We are working on a Firmware Update that will work in these applications. We do not have a ETA for this right now. (Source)
Download: www.crucial.com/support/firmware.aspx (Direct Link)

Code:
Change Log
* Changes made in version 0002 (m4 can be updated to revision 0309 directly from either revision 0001, 0002, or 0009)
* Correct a condition where an incorrect response to a SMART counter will cause the m4 drive to become unresponsive after 5184 hours of Power-on time. The drive
will recover after a power cycle, however, this failure will repeat once per hour after reaching this point. The condition will allow the end user to
successfully update firmware, and poses no risk to user or system data stored on the drive.

This firmware update is STRONGLY RECOMMENDED for drives in the field. Although the failure mode due to the SMART Power On Hours counter poses no risk to
saved user data, the failure mode can become repetitive, and pose a nuisance to the end user. If the end user has not yet observed this failure mode, this
update is required to prevent it from happening.

If you are using a SAS Expander please do not download this Firmware. As soon as we have a Firmware Update that will work in these applications we will release it.