I never speak to anyone when I enter a room unless they say something before I get to the quest machine. I head right for the quest machine and up pops the quest. I wouldn't know if they were talking to me or not.
If you want to stop mules from overrunning your quest then make sure that your good prizes are not in the top ten or so spots. Then they will not have any idea where there ranking is at and at the same time you will be helping those who are not good at quest or have a hard time with their computer. This will help those to have a better chance.
Another thing to do would be to make your quest longer time wise. If your scared of someone playing ten players and your quest takes a half a hour or more to do, do you really think they will stick around and keep playing all there mules through it.
If you want to stop mules from overrunning your quest then make sure that your good prizes are not in the top ten or so spots. Then they will not have any idea where there ranking is at and at the same time you will be helping those who are not good at quest or have a hard time with their computer. This will help those to have a better chance.
Another thing to do would be to make your quest longer time wise. If your scared of someone playing ten players and your quest takes a half a hour or more to do, do you really think they will stick around and keep playing all there mules through it.
My In Park character had turned out just fine though; it only took me awhile to figure out the email I registered under! 
. This is how I'm postive I've been overrun with mules: I know how long it takes to complete my quest without reading the task clues (my test time). So I have a pretty good idea what the fastest possible times could be (plus or minus 20 or so seconds depending on load time and computer speed). When I say "record time" I mean the players who beat my time to complete my own quest. Which I know is impossible.....unless you know the quest already and don't need to read the clues or look through the answers. I have a few repeat questers who like to come by when it's open fairly regularly. Players I've gotten to know and have befriended on VMK. Even they can't beat the mule times because of the little tweaks and changes I like to add...and they are very familiar with my quest. Whattacanoworms though!
