can house elves apparate in Hogwarts?

[kyliemckenzie1225]

No: HPFGUIDX 84566

kylie:
I have resurrected this question since this subject still bothers 
me...does anyone have an answer?

in a previous post, samnanya remarked:

<snip><finally,
You cant apparate in Hogwarts (its been said so many
times by so many different characters that I am
suspicious, but thats me)>

Now me(kylie):

This reminded me of a question I had while re-reading CoS. While
Harry is in the hospital wing regrowing the bones in his arm, Dobby
appears for a second time. When they are interrupted, we
read " 'Dobby must go!' breathed the elf, terrified. There was a
loud crack, and Harry's fist was suddenly clenched on thin air."

We have read that this sound is supposedly connected to apparation,
for instance, in Chapter 1 of OoP, after Harry is caught listening to
the news, "Harry was sure that the cracking noise had been made by
someone Apparating or Disapparating. It was exactly the sound Dobby
the house-elf made when he vanished into thin air."

so, my question is.....(okay, maybe I am missing something obvious,
but...) are house-elves an exception to the rule that no one can
apparate into or disapparate from within the grounds of Hogwarts? Is
there a different kind of magic (i.e., not apparation) going on
here? Can someone explain? thanks!

kylie