Pointer stored in wrong code class.

Can anyone tell me why the following code for the C167 will place the pointer in either the NDATA0 class or the XDATA0 class depending on which line is uncommented?

typedef struct
{
short type;
} DIR_ENTRY;

typedef DIR_ENTRY xhuge * DIR_PTR;


//DIR_PTR test1; // Pointer placed in the XDATA0 class.
DIR_ENTRY xhuge * test1; // Pointer placed in the NDATA0 class.

I am using version 4.06 of the compiler.

Thanks.