Ya, thot so. Vague memory of being told, "That's illegal," when someone burnt a bill in protest or for a magic act or something.
Thanks for not taking my mention as an argument against your stance, as I also do not speak for the US govt (tho as a citizen of the US, I can - the whole of the people thing).
Plus, I feel better about my other reply to the parent, er, maybe gp, post when I said that burning money is as "wrong" as burning a book - both only have value that we assign to them, rather than an intrinsic value. Merely, we've assigned a very high value to a publication if it's money (so much so it is, indeed, illegal to burn it and therefore any exception to First Amendment protection is probably handled on a case by case basis).
As you state, Flag burning is more apt as a comparison to book burning (especially that it's codified by a 1989 Supreme Court ruling).
Ya, I've been all over different discussions about the whole 451 acts lately, being a literary buff and all; which is the only reason I now know that about flag burning laws.