Sony USA has released a firmware update for the A17. LINK, this should work for the A15 but update at your own risk. I have not seen the update on Sony Europe's site yet.
Benefits provided by previous updates and included in version 1.21:
- The memory type (such as a built-in memory/SD card) can now be selected even while connected via USB
- Addresses an issue where, in rare cases, sound may not be produced when the WALKMAN is connected with the digital amplifier
- Provides additional function updates
- Supports LDAC (a newly developed high resolution codec) during Bluetooth® connection.
- Improves a condition where the Walkman may be slow in action when a FLAC (Free Lossless
- Audio Codec) file, which has more than one jacket picture, is played and moves to the next or previous song
- Download the NWZ-A10_V1_21.exe file to a temporary or download directory (please note this directory for reference).
- Connect your Walkman player to your computer using the supplied USB cable.
- Go to the directory where the file was downloaded and double-click the NWZ-A10_V1_21.exe file to begin the installation.
- Carefully follow the onscreen prompts to complete the installation.
Note: During the update the USB connection is automatically controlled and the Connecting USB message is not displayed. On some computers a USB Disconnect message may be displayed.
When the Completed message is displayed, click Finish.