[HPforGrownups] OK... theory I read while I was gone

[Pauline]

No: HPFGUIDX 56919

Darrin quoted 
Here is the evidence, fairly shaky, but here it is.

>PoA, pg 68: "Are you all right, Harry?"
>Harry didn't ask how Prof. Lupin knew his name.

I imagine, as well as the physical similarity to James, most of the kids in
the carriage were calling Harry's name when he passed out, or Lupin could
have been awake some or all of the time he appeared to be dozing whilst
they were travelling in the train.  

Lupin's distrust of Sirius still fits, and when he finds out Sirius 
wasn't the betrayer, his relief does as well.

James should have known who the secret keeper was, even if he and Lupin had
switched bodies. 

Interesting, thanks Darrin

Pauline