diff -urN ecos.orig/packages/hal/arm/lpc2xxx/var/current/src/lpc2xxx_misc.c ecos/packages/hal/arm/lpc2xxx/var/current/src/lpc2xxx_misc.c
--- ecos.orig/packages/hal/arm/lpc2xxx/var/current/src/lpc2xxx_misc.c	2006-05-05 19:42:04.000000000 +0300
+++ ecos/packages/hal/arm/lpc2xxx/var/current/src/lpc2xxx_misc.c	2006-05-06 00:48:38.000000000 +0300
@@ -249,6 +249,12 @@
 
 void hal_interrupt_acknowledge(int vector)
 {
+    if (vector <= CYGNUM_HAL_INTERRUPT_EINT3 &&
+        vector >= CYGNUM_HAL_INTERRUPT_EINT0) {
+        vector = 1 << (vector - CYGNUM_HAL_INTERRUPT_EINT0);
+        HAL_WRITE_UINT32 (CYGARC_HAL_LPC2XXX_REG_SCB_BASE +
+                         CYGARC_HAL_LPC2XXX_REG_EXTINT, vector);
+    }
     HAL_WRITE_UINT32(CYGARC_HAL_LPC2XXX_REG_VIC_BASE +
                      CYGARC_HAL_LPC2XXX_REG_VICVECTADDR, 0);
 }