Is anybody here having problems playing the Apple HD demos with surround sound? I get only the front speakers and nothing from center, surround and LFE channels.

this was allready reported by some users, but did you check the qt settings?

There is a bug, it appears, in Quicktime's 5.1 audio modes on CREATIVE soundcards-- I cannot get the center channel to work on these soundcards:

Creative Audigy
Creative Audigy 2
Creative X-Fi XTremeMusic

I've tried reporting the issue to Apple and Creative; Creative told me that they can't offer support because they don't make Quicktime (what a lame response.) And Apple never responded to me!

So, yeah. I guess we'll have to wait for the new version and hopefully they fix their surround sound implementation.

Does anyone knows if this got fixed in QT 7.1 ?

Edit:
It seems it's fixed, Silent Hill and Goblet of Fire HD trailers sound just fine on:
- windows xp
- audigy 2 nx
- 7.1 speakers

Can you post a link to the files?

The only HD demos I found on apples website were in stereo.