Vista - Vista Home Premium: Forced Subtitles not appearing for DVDs.

I have a number of problems with subtitles with my VMC running Home Premium.
Bear with me while I explain, as I feel they might be related, and if anyone
can shed some light on a solution it'd be appreciated

Issue 1: Watching 'Atonement' there is a section where people speak French.
This would normally be accompanied by subtitles in English. These are 'forced
subtitles' and appear automatically (e.g. the elves' speech in LOTR).

However, they didn't appear in this case. If I switched subtitles on via the
CTRL+U shortcut., or the VMC DVD settings menu, they appeared - but so did
all the subtitles for the movie (i.e. all dialog was now subtitled).

Issue 2: I tried watching 'Amelie' (a disc image ripped and stored locally).
This time I tried setting the subtitle options from the DVD menu on the disc
itself. This made no difference and subtitles weren't displayed. Again, using
CTRL+U or the DVD settings menu in VMC would make them show up, but then this
would remain set for all subsequent films whether I wanted subtitles
displayed or not.

The frustrating thing about both of these issues is that if I used Vista
Media Player both films behaved correctly - 'Atonement' showed forced
subtitles at the appropriate time and 'Amelie' could have subtitles set by
the DVD menu - however as my PC is used primarily for media via the remote
control this isn't much use.

Is there something fundamentally wrong with VMCs DVD playback, or am I
missing a setting somewhere? Forced subtitles should be respected, and menu
selections from the DVD menu itself (e.g. subtitles, audio commentary, etc)
should be remembered and the appropiate setting used when playing the movie.

Any ideas?