Dobby and Hogwarts

[Marty Larson]

No: HPFGUIDX 104230

As I'm sure many of you are doing, I've been rereading CoS and this 
time through I was struck by this - Dobby just appears in the 
Hospital wing while Harry is regrowing his bones and with a crack is 
gone when he hears someone coming.  (Not quoting as I don't have my 
book handy).
As we have read many times, no one is supposed to be able to 
disparate or apparate within Hogwarts.  Is Dobby going to the 
kitchen to be with other house elves or is the house elf magic so 
different as not to be ncluded in the Hogwarts restrictions?

Just wondering,
larsonmart