The Software Update version 7.2.3 for the Amazon Kindle Fire HD 7" Tablet is now found on Softpedia. This package includes, as Amazon vaguely says, bug fixes and performance improvements.
There is no list for the exact fixes or improvements, although some users claim that it resolves the turning off predictive text issue, as well as the calendar destruction after an update problem.
If you consider updating, first go to More → Device → About to check your current version, and if it isn’t 7.2.3, then you are not up-to-date.
So, copy the downloadable file into the “kindleupdates” folder on your device, ensure that the transfer is complete and successful, and afterwards go to More → Device → About → Update Your Kindle.
The update is started through an automated system restart. When the process is finished, the device will restart one more time, and if it was successful, the system version must now be 7.2.3.
This said, if you want to update your Kindle, follow the link below and stay up-to-date.