Problems with tellsimp



I'm sorry to bother the list, but I'm confused about the tellsimp command.

If I execute the following commands:

nary("nOR",100);
declare("nOR",commutative);

matchdeclare(pat , all);
tellsimpafter(pat nOR false  , pat );
tellsimpafter(pat nOR true   , true );


(%i10) false nOR x;
(%o10) x

as expected, but

(%i11) false nOR false;
(%o11) nOR(false,false)

Why does this not also simplify to false?

Thanks,

Chris