i think what salim is trying to say is, that in the hand posted above, in that spot, queens shld always fold. even if the 2 villians had the stacks for u to try and setmine, knowing that u're beat, the $12 raiser is not going to flat call the extra $20, not with u in the hand as well. he's going to raise 100%, and aces prob reraise again, which is why tryin to setmine in that spot is 100% -ev.
however, if it were headsup, for example, stacks are very deep, $800 each in a 1/2 game. if u raise to $6 pf and get repopped by villian to $12, reraising here will tell u where u are at, perhaps to $38. if he can come over the top again, making it $100 to go, even if u know he has KK or AA, u should almost always call here. both of u have $700 behind, u're definitely getting the right implied odds to try and hit your set.
hope that makes sense.