Harry and the Imperius Curse... how many times?

[btk6y]

No: HPFGUIDX 33073

Surely this has been discussed, but I am just looking for an answer.  
In GoF, Moody put Harry through the Imperius Curse "four straight 
times" until he could completely throw it off.  However, when he and 
Voldemort are dueling, the book says that Harry felt the bliss of the 
Imperius Curse "for the third time in his life".  What's up with 
that?  When was the second time?  Even if you look at the prior 
lesson as a different episode each time he went under the curse, then 
it would have been the fifth time when he was dueling Voldemort, not 
the third.  One more note dealing with the Imperius Curse and Ron's 
character.  Moody specifically states that it takes a "lot of 
character" to throw off the Imperius Curse, and compares your ability 
to throw off the Imperius Curse directly with the amount of character 
you have.  He does NOT mention at any time that the ability to throw 
off the Imperius Curse is at all related to DADA ability, only 
character.  Now, character is a nebulous term to begin with, I 
suppose, but I take character to mean all that good stuff like 
loyalty, integrity, honesty, etc.  Given this (which you may not 
agree with), and considering that Ron had a very "difficult time" 
throwing off the Imperius Curse, does this forshadow an eventual 
betrayal by Ron, intentionally or not?  My gut says no, but I think 
it's an interesting bit of foreshadowing that is not there for no 
reason.  All thoughts are appreciated.

Bobby