I was re-reading Deathly Hallows, and I stumbled across a passage in there that stated that Mad Eye had left curses against Snape to prevent him from getting into Grimmauld Place.

However, Rowling stated just pages before that Dumbledore was Secret Keeper for Grimmauld Place, and when he died, all those that knew the secret were now Secret Keepers themselves.

My question is, if Dumbledore's secret gets passed on to others because he is dead, then how did Mad Eye's curse stay against Snape? I was under the impression that when a wizard dies, all the magic they produced disappeared. Is this not the case?

What do you think about this?

i really didn't understand why the dust monster died when harry said dombledore he didn't say the whole phrase that lupin said why did it dispurst?

I think it's cause dumbledore is dead, dumbledore allowed Snape into Grimauld place but since Dumbledore is dead the curse madeye put against snape entering Grimauld Place worked cause Mad eye Moody was not dead at that time.

I thought that they put a tongue tying curse on Snape so that if he talked about Grimauld place his tongue would get tied . . .? Or something . . .?
Yeah I'm not sure.

Yeah you got a point, but I think while Moody was alive, Snape'd tried to talk but when he couldnt, they let it go. They knew the Order had left the place, so why bother so much? Then Hermoine let Yaxley (it was Yaxley, right?) in after a month anyway.

Why does Moody have to do that?! What a rip off

That part's unclear. The dust monster and what it was supposed to do, I mean. There must be some way it was to identify Snape. But then Harry didn't know abt it, so......it is confusing. Whatever the curses were, Snape went through them.
And, yes, there were some curses. That much is certain.