Leonardo said:
You can't fix that. You can't "un-mix" stuff from a soundtrack. Unfortunately all those tracks are stuck like that, I'm sad to say.
I'm not sure about that... the italian soundtrack is (should be) Dolby Surround encoded, thus have the left, right, central and surround channels encoded into a stereo track; decoding those channels, is it possible to take only the central one and including it in the corrispondig place of, e.g., the english AC3 5.1 soundtrack; the quality will not be the same, as the best Dolby Surround ProLogic decoder has around 40db of separation, but should be sufficient to result into a better surround italian soundtrack than the original; the same could be done for the other languages... mmmhhh, you inspired me a bit...
Windows Media Player and VLC. On the former I can turn them on, but I can't select the track, and the first one doesn't work. On the latter I can see all the sub tracks, but as I said only the second one works.
As I'm against Windows Media Player, I couldn't tell anything about it, but in VLC it works well.. just play the file; under "Audio/Traccia Audio" you should see "Disabilita|Traccia 1 [italian]|Traccia 2 [english]"; under "Video/Traccia Sottotitoli" you should see "Apri file|Disabilita|Traccia 1 [italian]|Traccia 2 [italian]|Traccia 3 [english]|Traccia 4 [english]" - the first is italian forced, the second italian full, third english forced, fourth english full...
If it doesn't work, download Media Player Classic - it's light, and works very well!