Ah, you never know what you'll learn about your DAW, even after years of using the same DAW, same version! Like me, right now I use Audition 1.5. I'm in multitrack mode trying to see if the audio from my double ender with Scott Massey will line up with my audio, but I spend 30 minutes trying to figure out why it won't let me adjust the sampling rate of Scott's file. Turns out that since I had loaded the file into the multitrack view before trying to convert it, it wouldn't let me adjust that parameter in the two track mode until I removed the file from the multi-track line-up!
Makes sense, but you'd think I'd have thought of that! lol.