Right - this time it's sorted!
That was hard to track down! The problem actually had nothing to do with the preview audio, it was a bug in the device selector component that only happened on Windows with a certain midi config.. Hopefully should be OK now.
Thanks for your patience, and sorry I didn't believe you at first, but I've seen countless threads like this in the past which turned out to be people not building the right folder!
Thank you, I'm glad you could find something. I'm looking forward to test after you commit the change.
I committed it before I posted my last reply.
Did you git-push? :)
Commits on Jan 4, 2016:
Whitespace; julianstorer committed 18 hours ago; 85cd905
Fixed a comment for StringArray::removeString that didn't match the …; julianstorer committed 20 hours ago; 5a5fa35
Added some null pointer checks to createWriterFor methods; julianstorer committed 21 hours ago; 3b88140
Deleted the old NPAPI/ActiveX juce_browser_plugin_client module. Th…; julianstorer committed 21 hours ago 400cd0e
Make bus count non-writable or simple effect plug-ins: this seems to…; hogliux committed 21 hours ago; 69d371d
Avoided a leak if the app is killed while an AudioDeviceManager is…; julianstorer committed 23 hours ago; c401515
Sorry, looks like something went wrong in pushing it - it's on github now.
Great!
Thank you very much for your support and for fixing it. 
