ATXMEGA 128 interrupt

Hallo ich kenne mich mit dem ATXMEGA noch nicht gut
aus. Kann mir vieleicht jemand sagen warum der Interrupt
immer 2 mal auslöst ?
Habe den Taster eigentlich entprellt.

$regfile = "xm128a3def.dat"
Rem $crystal = 2000000                                          '2MHz
$hwstack = 64
$swstack = 40
$framesize = 40
'crystal = 2000000
$crystal = 32000000
Config Osc = Enabled , 32mhzosc = Enabled
Config Sysclock = 32mhz
$lib "xmega.lib" : $external _xmegafix_clear : $external 
_xmegafix_rol_r1014
Config Priority = Static , Vector = Application , Lo = Enabled
Config Pind.5 = Input
Config Portd.7 = Output

 Config Eeprom = Mapped
Config Com1 = 19200 , Mode = Asynchroneous , Parity = None , Stopbits = 
1 , Databits = 8
Config Lcdpin = Pin , Db4 = Porta.3 , Db5 = Porta.4 , Db6 = Porta.5 , 
Db7 = Porta.6 , E = Portb.1 , Rs = Porta.7
Config Lcd = 16 * 4                                         'configure 
lcd screen
Config Lcdbus = 4


On Portd_int0 Port_d_int0__isr
Enable Portd_int0 , Lo
Enable Interrupts


   Portd_pin5ctrl = &B00_001_010
   Portd_int0mask = &B0001_0000
   Portd_intctrl = &B0000_00_01
        Cls
        Lcd "Interrupt P"
    Do

    Loop

    End

Port_d_int0__isr:


       Lcd "1"
      ' Toggle Portd.7
      ' Lcd "interrupt P"
Return