Olympus recently released a firmware update for the Olympus DM2 & DM4 digital voice recorders. Attached, you will find release notes for this update.
http://www.zazaknowledge.com/resources/13756/DM-4_DM-2_FW11_ReadMe_EN.pdf
The firmware update version 1.10 can be found on our FTP site.
Verification Source: In-house testing