Situation: You are installing the PDF Ifilter on a MOSS server, and you want to follow Deb Haldar’s instructions, but you are installing Acrobat Reader v 8.1.1, not 8.0. Fear not! Once you have installed Reader 8.1.1 on your MOSS server, If you search the Registry for the CLSID GUID {E8978DA6-047F-4E3D-9C78-CDBE46041603} , you will find an entry that shows it does indeed still point to ProgramFiles\Adobe\Reader 8.0\Reader\AcroRdIF.dll, which is still the correct path.
–Michael