Matrox IFrame codecs not installing in AME

I'm running Media Encoder CS4 on a Windows XP machine.  After a  BIOS issue I won't bore you with, I had to repair my machine and reinstall CS4.  I have always used Media Encoder to convert our ProRes files to the Matrox IFrame codec to use in our Crossfire for playback.  But when I reinstall the codecs, they don't appear anywhere in Media Encoder.  The Matrox installer says that the codecs are installed, but Media Encoder doesn't seem to see them, and they don't appear in the list.  Do I have to drag something into a specific folder?

Thanks!