at91rm9200 ExecuteITHandler parameter bug

[Haberhausen, Dierk]

Hello,
I was wondering why my ISR don't get the interrupt vector parameter. 
I found out that the ExecuteITHandler function,
don't consign this parameter to the ISR
(rtems-src\c\src\lib\libcpu\arm\at91rm9200\irq\bsp_irq_asm.s).
So I have changed the ExecuteITHandler to:

ExecuteITHandler :
/*
 * Look at interrupt status register to determine source.
 * From source, determine offset into expanded vector table
 * and load handler address into r1.
 */
        ldr     r0, =0xFFFFF100   /* AIC_CTL_BASE + AIC_IVR */
        ldr     r1, [r0]                
        str     r1, [r0]          /* write back in case we are using protect
*/

        ldr     r0, =0xFFFFF108   /* AIC_CTL_BASE + AIC_ISR */
        ldr     r0, [r0]          /* Read interrupt vector  */

        stmdb   sp!,{lr}
        ldr     lr, =IRQ_return   /* prepare the return from handler  */

        mov     pc, r1            /* execute handler */

But I am not sure that I get the right vector in all cases (nested irqs)??? 
Has anybody a deep knowledge in the ATMEL AIC? 
Thanks and nice weekend... 
Dierk