using VMO 4.2.2 or 5.0.1 the play button does not appear to work if the device is set to playback on the PC. it can play back on the phone, or in Windows media player by double clicking on the wav file. Codec used is G.711. we are using Outlook 2007 in this case. Also it appears to have broken when installing an MPEG2 codec pack, which has since been uninstalled.