bug ? "unknown argument combination"

Hi,

If I have 5 arguments or more (code below), my object (built with sdk 5.1.7) won't be instantiated in Max 6.1.2, and I get the following error :

Test: 139810: unknown argument combination

If I remove 1 argument it gets instantiated correctly. So has Max 6.1.2 introduced a limitation on the number of arguments ?

With Max 5 or Max 6.0.8 everything is fine.

I know I can use (t_symbol *s, short ac, t_atom *av), but is there any reason the code below won't work in max 6.1 while it was working in earlier version?

#include "ext.h"
#include "ext_obex.h"

//==============================================================================

void *Test_class;

typedef struct _Test
{
    t_object x;

} t_Test;

void *Test_new (double a, double b, double c, double d, double e);

//==============================================================================

int main (void)
{
    t_class *c;
    c = class_new ("Test", (method) Test_new, (method) NULL, (long) sizeof (t_Test),
                0L, A_DEFFLOAT, A_DEFFLOAT, A_DEFFLOAT, A_DEFFLOAT, A_DEFFLOAT, 0);

    class_register (CLASS_BOX, c);
    Test_class = c;

    return(0);
}

void *Test_new ( double a, double b, double c, double d, double e)
{
    return (t_Test *) object_alloc (Test_class);
}