Forum:The Cloak of Invisibility

I'm new at this so.. here goes:

I've just recently been rereading all of my Harry Potter books to refreshen my memory for the sixth movie release. Amongst reading the seventh book last night, I came to a part that left me confused. As we remember in the 6th book, when Dumbledore was being comfronted by the Death Eaters and Malfoy before Snape killed him, Dumbledore stunned Harry while he was wearing the invisibility cloak so that he could not move or be heard. In the 7th book it says that the Cloak of Invisibility cannot be penetrated when Harry finds out about the Deathly Hallows? Maybe I haven't read far enough yet to find the answer, but this seemed strange to me. Doesn't Harry have THE cloak in question?

Thanks, Stacey