[DDDamian]

Okay - new build up. Direct link XBMC-AE-20120406.zip or link from first post and check newest date.

Changelog:
- use old-style WAVEFORMATEXTENSIBLE structure for backwards compatibility
- use WAVE_FORMAT_DOLBY_AC3_SPDIF format for backwards compatibility
- fix DTS breakage - works on my setup with DTS, DTS-HD (24/96) and DTS-MA
- fix double sink opening for quicker skip/seek and hopefully no receiver switching from encoded->pcm
- fix buffer sizing in CSoftAEStream
- add dynamic Stereo to All Channels upmix for stereo music/videos
- fix crash on deselecting MultiChannelLPCM capable receiver button
- a few other invisible tweaks

Tested on just about all formats on my setup:
Win 7 x64 Premium
ATI HD6450 GPU
Catalyst drivers 12.1 w/AMD High Definition Device Driver 7.12.0.7705 12/06/2011
HDMI to Denon 3808CI

Tested: AC3 2.0/5.1, DTS 5.1, DTS-HD 24/96, DTS-MA, AAC, TrueHD, mp3 video soundtracks
Tested: mp3, FLAC stereo and m/c from 2.0 16/44.1 to 5.1 24/96

I am using WASAPI, exclusive mode, HDMI, 7.1 channels. Just about any video settings have worked fine.

Note: please start with your audio buffer size around 50msec - I set the default a bit high and found it can overrun buffers on high-bitrate audio - I'll fix that in the next build. For now just go to the Audio Output settings page and reduce it to 50msec to start, higher only if required.

As always, full debug logs with any issue - all feedback, good and bad is welcome!