Dumbledore Wrong?

[Kimberly]

No: HPFGUIDX 145375

> graverobber: 
>  So there are actually 5 horcruxes still
> out there. 
> 1) Hufflepuff's cup, 2)Something of Griffindor's, 3)
> Slitherin's 
> Locket, 4) Nagini, and 5) LV himself. (HBP)
> 
> Now the true question is.... What is the thing from
> Godric 
> Griffindor? My thoughts are on Godric Griffindor's
> sword.
> 
> 

Kimberly here:
I would agree that one of them is something of
Gryffindor himself, however, as for the sword:

"I am confident, however, that the only known relic of
Gryffindor remains safe."   
Dumbledore pointed his blackened fingers to the wall
beind him, where a ruby-encrusted sword reposed within
a glass case.

HBP, Amer. ed., p. 505


Now, is this an instance where Dumbledore is mistaken
or JKR telling us it's something else ?

Kimberly