Can anyone explain why PowerPoint 2007 only accepts WAV files when attaching them to items via custom animations but will accept any kind of audio file including WAV files when embedding them via Insert/Sound?

"Insert/Sound/From File" permits all kinds of file types but when adding audio to a Custom Animation only WAV files are permitted. Seems strange to me.

Also, I have numerous MP3 files that have been "squashed." Their sizes are about 7000 KBs. When I edit them through Audacity and export the final version, the size is around 21000 KBs. The original file as well as the edited file will play via Insert/Sound... as well as Custom Animation... but if I compress the edited file using Microsoft's Sound Recorder, the sound will not play either from Insert/Sound or Custom Animation.

Can anyone help as I need to reduce the file size of the PPT (Single slide plus audio) so that I can create a smaller WMV file.

Thanks in advance!