I'm still having this problem in r98. I can import the wav just fine, but when I try to play it, it kills all audio in the layout. I've tried encoding the wav files from Audacity, MediaMonkey and LMMS. They are all encoded at 44.1khz.
edit: firebug doesn't show any script errors but the polls to the server are failing, and the editor can't relaunch the demo server until it's been closed and reopened.