Audio doesn't play audio on separate audio-video .ismv files

Roku player fails to play audio on Smooth streaming .ismv files that do not contain audio track. Audio track is found in a separate .isma file. When playing this files the player only display video but no audio.
Looking at the manifest file the video files (.ismv) only contains a video track the audio track is found on a separate (.isma) file. The Manifest file can be played correctly on Silverlight players and in IPOds.

Here is the manifest example:

<?xml version="1.0" encoding="utf-8"?>

I have done extesive tests! It works fine when video and audio are muxed in the same .ismv file,

Is there a fix available that addresses this playback issue? Or is there a solution where I can tell the ROKU player to look at two separate files for Video and Audio to playback at once?

Thank you for your help.

Regards,

Art