Yes...the software is installed and the files we've been looking for happened to be 64-bit.
Anyway, I ended up opening a support case with Symantec awhile ago where even the analyst was stumped. What seems to be happening is inventory's somehow getting flushed periodically where my monthly full inventory brings everything back. I have no idea how long it takes before it disappears again and at this time since my monthly full hasn't run yet, I can tell that inventory's amiss once more.
Guess I'll open up a new case with Symantec in hopes that someone can figure out exactly what's going on with my SMP server.