Problem while freeing allocated memory

dear all,
I don’t understand what’s wrong in this and why it’s wrong…

I’m allocating memory in this way

TH1F *h = new TH1F[1000];

and this is fine, but when I try to free the memory I get this error

delete h;

*** glibc detected *** free(): invalid pointer: 0xa5afa00c ***

The strange thing is that if I allocate less memory

TH1F *h = new TH1F[10];
delete h;

it works without any error.

who can help me?
thank a lot

delete [] hJan