The players in my campaign are all good enough at roleplaying not to use info from previous experiences (not to mention the amount of changes I've made in customizing and converting the module). However, the hunter of the dead's reaction was a definite tip off ("It's not real- it's just a legend! It can't be..." I told them he'd gone bone white and was looking scared, when they'd never seen him act other than fanatically devoted to destroying undead).
The high-level part in my campaign has apparently forgotten that most important of lessons in dnd- sometimes you should FLEE!!! They haven't fled a battle, even when badly outclassed, since- well, I can only remember one time when they fled in the last few years, frankly.
Even when the party's studly 19th-level fighter attacked with everything thrown to offense (i.e. no power attack), he missed with his primary attack on a natural 19. That was a clue, too.
Sigh... well, they're still puzzling over the riddle. We'll see what happens next time we play that group- I suspect, however, that we'll play my halfling game next.