So anyway, everything else is working (w.r.t videos in Powerpoint) except for mpg files. This is the related debug message from Wine. Code: fixme:quartz:MPEGSplitter_query_accept MPEG-1 system streams not yet supported. And the error message from Powerpoint:- Code: Windows Media Player cannot play the file. The file is either corrupt or the Player does not support the format you are trying to play.%0 Note, this is easily replicated in a fresh Wine install without Office 2007, just install Windows Media Player and try to play an mpeg/mpg file. Should I file a bug? Am not sure on the procedure for doing so/assigning the bug etc.etc. for Wine.