I have never seen the specific question asked but I am pretty sure the chips in the pot are not part of the muck. The muck is any dead cards. The rule is in place to make sure that someone hand cant re-emerge from the muck with a different card or cards.

Muck is the dead cards...specifically, the folded ones...not the burn cards of the board.

Thanks to everyone for this post - Will print this for my trip

Rh covered pretty much everything I can think of (great post! We should get tetsuo to put this somewhere for "posterity" imo).

A few elaborations, really, on points already made: I do see players putting in the wrong number of chips sometimes (typically less than required, of course) and sleepy dealers missing it. I usually only say something if I'm involved in the pot, but I probably should otherwise, too, as it's a problem that effects the whole table and should be noted.

On showing cards: I had one where a player insisted that I turn over my cards after he rivered a flush on my TP with AK in a pot of over $1,000. I should have just thrown them at the muck (that was a new one for me and very good point) once he turned over his cards. But what I did after that was insist that he turn over his cards on every single hand he wanted to muck, whether I was involved in the pot or not. Anyhow, it was probably a bit of an over-reaction on my part, but there are at least possible reprisals for breaches of etiquette there (I was particularly aggravated due to losing this huge pot anyway, so the insistence on turning over my cards was more than I cared to deal with).

P.S.: In our game, the muck is usually just to the left of the dealer. So it's sometimes difficult to get the cards there if you're at the far end of the table.

...you have to get good at pitching into the muck from across the table

I like this thread...good for online players. I'm a live pro and I havent seen any false info here, but a few things were left out. All the upcoming tips are things I regularly practice at foxwoods so its prolly cool to do anywhere but who freaking knows. (except #1)
1. Most casino's do anything and everything they can to keep you "in line". So you really have to kindof stay out of their eyeline (the floor), do what they tell you, and attmpt to break the rules quietly if your gonna. The floor is the final say in any dispute/rule/etc so dont bother arguing and dont be afraid to call them over to settle an arguement. P.S. dont listen to they're bullshit on ettiquette, simply say what is the rule here sir?
2. As previously mentioned always announce your raises when you arent used to live play; but once you get a feel for it just simply say raise, call the bet, then count down your raise behind your cards/the bet line, then just push the chips in. The angle here is to catch a read off your opponent by just saying raise and causing them to feel uncomfortable w/ the anticipation. Also it minimizes the risk of your opponent catching reads off you. You also wont have any "string" issues and get a few seconds to figure out the right number.
3. A little trick in live play: When you are going to raise w/ the nuts...well you want a call use big chips. instead of betting 200 w/ 40 red chips bet 200 w/ 2 black chips or bet 225 w/ 2 black chips and a green. Bad players who dont use math in their games will look at the bet as 3 chips as opposed to 225 or 45 chips as opposed to 225. Obviously a good/math oriented player wont be affected as much, but give it a shot...you'll be surprised how often you'll get the nuts called by midpair.
4. Psychology: online play is all about math, combos, aggression. Its very easy to be aggro and think on your feet when the other guy cant see you, but when you have a 46 year old business manager who makes his living negotiating and interviewing people good luck not getting a little put off. Little known facts about shitty poker players are that they might be stupid at the math of poker, but they will put you off your game beautifully (see #5 for a brutal one). Also dont be afraid to look another player in the eye...do they look bewildered at the hand? where are they looking? where are they're hands? Just remember live cash is a beautiful thing...its people looking to gamble...know your table and pick your spots. Very key piece of advice: if your playing 1/2 at foxwoods you can pretty much give up on bluffing/being aggro; it works like 5% of the time, however if you have top pr beat on the flop, bet your ass off and you'll get payed way better than you ever would online. 1-2 live=.2/.5cent online.
5. Hypnosis: yeah believe it or not you can "hypnotize" people. Scottie Ngyen does it. Be nice to other players cause it's +EV. They'll take a fun/joking tact w/ they're bets, lose more graciously, and be apologetic at a win. Makes things way easier for you w/ your draws or bluffs. Ever had someone cock they're head at you and say "heey buddy" looking all romantic (uncles esp.) and you get a fuzzy feeling in your head (pleasurable) but find it difficult to think clearly? I forget the actual term for it but its a negotiation tactic used by businessmen to get what they want. Its an oedipus/fruedian mommy thing that makes you more trusting/passive.
Sorry for the length, final chapter of this book:
6. Slowrolling: God if you need this post I hate you. Slowrolling is the worst thing you can ever do to someone and I personally want to shoot anyone who does it. I have one strong rule here: if you slowroll someone in my presence im gonna do it to you in the worst way you can ever imagine. 2k pot, all your chips in, you have the 2nd nuts and are super confident. "wow, thats so sick man, jeesus, nice way to lose 1k...I mean look at my hand...OOPS FUDGE YOU SIR"--me
I have more of these but this post is already too long to read unless you really want to learn to play live. GL sirs and Foxwoods has the best cardroom on the planet structurally and size wise....WOODS FTW