*stubs toe in the dirt*
Rats! I had a whole theory about Ginny still being connected to Voldemort and him using that to manipulate Harry...then found this, from an interview with JKR on July 16, 2005, HBP publication day
Edinburgh, Scotland :
QUOTE
MA: Someone put it to me last night, that if Ginny, with the diary -
JKR: Harry definitely destroyed that piece of soul. You saw it take shape, you saw it destroyed, it's gone. And Ginny is definitely in no way possessed by Voldemort.
MA: Is she still a Parselmouth?
JKR: No.
And my story was soooo good. *sigh*