I followed your steps to the letter, but under messages Magic Bullet says it’s now able to convert my PAL interlaced footage to 23.976 fps.
Here’s the issue: my footage is not PAL. It’s the same NTSC footage I used yesterday, and After Effects thinks the projects and compositions I created prior to this morning now contain PAL clips. I had this problem a few weeks ago and was only solved by reinstalling After Effects.