Hi again,
As you say, the links work fine, regardless from the browser used. So with links, the Realplayer software or compatible players, e.g. Mediaplayer Classic are launched and playback is no problem.
This leads me to think it's not really an issue with the player software, but with how the browsers interpret the media filter code: Firefox reports that regardless of which RealPlayer version is installed a plugin is missing, and it wants 10.5, which then fails to install. Manual installation, reinstallation, clean installation: nothing makes this work.
IE shows a player interface on the page and will actually play it when the playback button is pressed.
There is, however, an error message saying: Done but with errors on page:
Line: 42
Char: 11
Error: No such interface supported
Code: 0
URL: http://moodle.org/mod/forum/discuss.php?d=95174
So my conclusion: there might be something in the php code that has changed since version 1.7.4. that does not work with Realplayer interfaces as before.
Any more thoughts?