Interesting that Apple was that much of their revenue. Reminds me a little of PortalPlayer from the iPod days, though it was much more dependent on Apple (90% of its revenue). But I remember the rumor mill echoed Apple was unhappy with them. Eventually, Apple decided to switch MP3 chip suppliers and the PortalPlayer imploded.
http://www.eetimes.com/document.asp?doc_id=1160843