diff --git a/gcode.c b/gcode.c
index 8a64a91..281a0ee 100644
--- a/gcode.c
+++ b/gcode.c
@@ -795,10 +795,11 @@ uint8_t gc_execute_line(char *line)
           break;
         case MOTION_MODE_PROBE:
           // [G38 Errors]: Target is same current. No axis words. Cutter compensation is enabled. Feed rate
-          //   is undefined. Probe is triggered.
+          //   is undefined. Probe is triggered. NOTE: Probe check moved to probe cycle. Instead of returning
+          //   an error, it issues an alarm to prevent further motion to the probe. It's also done there to 
+          //   allow the planner buffer to empty and move off the probe trigger before another probing cycle.
           if (!axis_words) { FAIL(STATUS_GCODE_NO_AXIS_WORDS); } // [No axis words]
           if (gc_check_same_position(gc_state.position, gc_block.values.xyz)) { FAIL(STATUS_GCODE_INVALID_TARGET); } // [Invalid target]
-          if (probe_get_state()) { FAIL(STATUS_GCODE_PROBE_TRIGGERED); } // [Probe triggered]
           break;
       } 
     }
diff --git a/motion_control.c b/motion_control.c
index 98956f7..a07af59 100644
--- a/motion_control.c
+++ b/motion_control.c
@@ -276,7 +276,14 @@ void mc_homing_cycle()
   void mc_probe_cycle(float *target, float feed_rate, uint8_t invert_feed_rate)
 #endif
 { 
-  protocol_buffer_synchronize(); // Finish all queued commands and empty planner buffer.
+  // Finish all queued commands and empty planner buffer before starting probe cycle.
+  protocol_buffer_synchronize();
+  
+  // After syncing, check if probe is already triggered. If so, halt and issue alarm.
+  if (probe_get_state()) { 
+    bit_true_atomic(sys.execute, EXEC_CRIT_EVENT);
+    protocol_execute_runtime();
+  }
   if (sys.abort) { return; } // Return if system reset has been issued.
 
   // Setup and queue probing motion. Auto cycle-start should not start the cycle.
diff --git a/nuts_bolts.h b/nuts_bolts.h
index 1acaf16..073ed3d 100644
--- a/nuts_bolts.h
+++ b/nuts_bolts.h
@@ -29,6 +29,7 @@
 #define X_AXIS 0 // Axis indexing value. Must start with 0 and be continuous.
 #define Y_AXIS 1
 #define Z_AXIS 2
+// #define A_AXIS 3
 
 #define MM_PER_INCH (25.40)
 #define INCH_PER_MM (0.0393701)
diff --git a/report.h b/report.h
index 4f1d768..71e636e 100644
--- a/report.h
+++ b/report.h
@@ -50,9 +50,8 @@
 #define STATUS_GCODE_INVALID_TARGET 33
 #define STATUS_GCODE_ARC_RADIUS_ERROR 34
 #define STATUS_GCODE_NO_OFFSETS_IN_PLANE 35
-#define STATUS_GCODE_PROBE_TRIGGERED 36
-#define STATUS_GCODE_UNUSED_WORDS 37
-#define STATUS_GCODE_G43_DYNAMIC_AXIS_ERROR 38
+#define STATUS_GCODE_UNUSED_WORDS 36
+#define STATUS_GCODE_G43_DYNAMIC_AXIS_ERROR 37
 
 // Define Grbl alarm codes. Less than zero to distinguish alarm error from status error.
 #define ALARM_LIMIT_ERROR -1
diff --git a/settings.c b/settings.c
index c64b0a4..451c8d3 100644
--- a/settings.c
+++ b/settings.c
@@ -25,6 +25,7 @@
 #include "protocol.h"
 #include "report.h"
 #include "limits.h"
+#include "stepper.h"
 
 settings_t settings;
 
@@ -194,8 +195,14 @@ uint8_t settings_store_global_setting(uint8_t parameter, float value) {
         if (int_value < 3) { return(STATUS_SETTING_STEP_PULSE_MIN); }
         settings.pulse_microseconds = int_value; break;
       case 1: settings.stepper_idle_lock_time = int_value; break;
-      case 2: settings.step_invert_mask = int_value; break;
-      case 3: settings.dir_invert_mask = int_value; break;
+      case 2: 
+        settings.step_invert_mask = int_value; 
+        st_generate_step_dir_invert_masks(); // Regenerate step and direction port invert masks.
+        break;
+      case 3: 
+        settings.dir_invert_mask = int_value; 
+        st_generate_step_dir_invert_masks(); // Regenerate step and direction port invert masks.
+        break;
       case 4: // Reset to ensure change. Immediate re-init may cause problems.
         if (int_value) { settings.flags |= BITFLAG_INVERT_ST_ENABLE; }
         else { settings.flags &= ~BITFLAG_INVERT_ST_ENABLE; }
diff --git a/settings.h b/settings.h
index 0d6b671..f741771 100644
--- a/settings.h
+++ b/settings.h
@@ -24,7 +24,7 @@
 
 
 #define GRBL_VERSION "0.9g"
-#define GRBL_VERSION_BUILD "20140725"
+#define GRBL_VERSION_BUILD "20140801"
 
 // Version of the EEPROM data. Will be used to migrate existing data from older versions of Grbl
 // when firmware is upgraded. Always stored in byte 0 of eeprom
diff --git a/stepper.c b/stepper.c
index 60a71ed..0ca2850 100644
--- a/stepper.c
+++ b/stepper.c
@@ -439,6 +439,19 @@ ISR(TIMER0_OVF_vect)
 #endif
 
 
+// Generates the step and direction port invert masks used in the Stepper Interrupt Driver.
+void st_generate_step_dir_invert_masks()
+{  
+  uint8_t idx;
+  step_port_invert_mask = 0;
+  dir_port_invert_mask = 0;
+  for (idx=0; idx<N_AXIS; idx++) {
+    if (bit_istrue(settings.step_invert_mask,bit(idx))) { step_port_invert_mask |= get_step_pin_mask(idx); }
+    if (bit_istrue(settings.dir_invert_mask,bit(idx))) { dir_port_invert_mask |= get_direction_pin_mask(idx); }
+  }
+}
+
+
 // Reset and clear stepper subsystem variables
 void st_reset()
 {
@@ -455,14 +468,7 @@ void st_reset()
   segment_next_head = 1;
   busy = false;
   
-  // Setup step and direction port invert masks.
-  uint8_t idx;
-  step_port_invert_mask = 0;
-  dir_port_invert_mask = 0;
-  for (idx=0; idx<N_AXIS; idx++) {
-    if (bit_istrue(settings.step_invert_mask,bit(idx))) { step_port_invert_mask |= get_step_pin_mask(idx); }
-    if (bit_istrue(settings.dir_invert_mask,bit(idx))) { dir_port_invert_mask |= get_direction_pin_mask(idx); }
-  }
+  st_generate_step_dir_invert_masks();
       
   // Initialize step and direction port pins.
   STEP_PORT = (STEP_PORT & ~STEP_MASK) | step_port_invert_mask;
diff --git a/stepper.h b/stepper.h
index a9ea766..35e4f2e 100644
--- a/stepper.h
+++ b/stepper.h
@@ -35,6 +35,9 @@ void st_wake_up();
 // Immediately disables steppers
 void st_go_idle();
 
+// Generate the step and direction port invert masks.
+void st_generate_step_dir_invert_masks();
+
 // Reset the stepper subsystem variables       
 void st_reset();
              
diff --git a/test/gcode/braid_cut2d.nc b/test/gcode/braid_cut2d.nc
old mode 100755
new mode 100644