Audio fallback flowplayer not working in IE 8

The flowplayer fallback for IE8 doesn't work :-(
There is simple no sound. IE9 and above: no problem, everything is fine.
Any idea how to solve that.
I need to ensure to be IE8 compatible

From what I assume, it could be the path to the uploaded mp3file in the flashvars, which looks like this on my side and seems to be weird

value="config={"buffering":true,"clip":{"url":"http://localhosthttp://localhost/drupal-4.com/sites/default/files/h5p/co...},"plugins":{"controls":{"fullscreen":false,"autoHide":false}},"playerId":"fp_30482751","playlist":[{"url":"http://localhosthttp://localhost/drupal-4.com/sites/default/files//h5p/c...}]}

the correct path, where it's located is here and plays neatly from there:
http://localhost/drupal-4.com/sites/default/files/h5p/content/3/audios/f...

value="config={"buffering":true,"clip":{"url":"http://localhosthttp://localhost/drupal-4.com/sites/default/files//h5p/c...},"plugins":{"controls":{"fullscreen":false,"autoHide":false}},"playerId":"fp_96941437","playlist":[{"url":"http://localhosthttp://localhost/drupal-4.com/sites/default/files//h5p/c...}]}
but should be

http://localhost/drupal-4.com/sites/default/files/h5p/content/3/audios/f...

... because in FF17 it still wants to fall back to flowplayer....

... the problem itself persists because even if I upload everything to my "real" webserver with a real domain etc. it messes up the path to search for the .mp3 file.
The workaround is to place now the .mp3 files outside H5P using the perfectly working mediaelement library, which is free and smoothly plays everything even in IE8. I would suggest to use this one iso the flowplayer one, because for the mediaelement there is already a Drupal plugin module available so one could combine it with H5P audio.
However: I tested the H5P video integration in the H5P presentation module and it plays w/o any problems even in IE8.

We've registeret this in our casetracker. Audio worked fine in IE8 before, we'll look into what has happened.