Ahhhh, interesting stuff about the codec here, explains why SP2 has issues and Mac:
http://ligos.com/index.php/home/support/indeosupport/
"Service Pack 2 - With the 2004 update to Windows XP (known as Service Pack 2), Microsoft has made changes to the OS and Windows Media Player 9 and 10 that prohibit the playback of Indeo content online. Users will find that they will no longer be able to automatically play video files posted on the web if they were encoded with the Indeo codec. Windows Media Player will only play Indeo files if they are local (on your hard drive). Questions and comments should be directed to Microsoft through one of their support channels."
and
"Indeo for Macintosh Platforms Indeo codecs are no longer offered by Apple for Macintosh platforms or QuickTime. There are no plans for an OS X version of the Indeo codecs."
Al