According to the gist translator here is a changelog for the DVR-A07-J firmware version 1.13.
DVD - R media 4X record quality improvement
+ R media 4X record quality improvement
+ R (CMC make) supporting 8 time fast corresponding new disk
The Japanese version 1.12 gist translation corresponded to the English version 1.12 changelog.
I am not responsible for the translation!
Remember, this firmware is for the Japanese version of the recorder (DVR-A07-J). It's better to wait for the English version.