Memory addressing problem with ez-usb (CY7C68013a)

 BYTE xdata u_buf1[1]         _AT_  0x4001;
 BYTE xdata u_buf[1]           _AT_ 0x4000;

void main(){

        int val;
        OEB=0xFF;

   u_buf[3]="a,b";
   u_buf1[3]="c,d";

     while(1){

        IOB=u_buf1[1];

   }
  }

I keil debugger memory window it is showing that both of variabls u_buf[1] and u_buf1[1] is storing at location X:0x0000.
Whether i assigned them different location.
and junk valu is displaying at 0x0000 location.