Index: trunk/FACT++/gui/FactGui.h
===================================================================
--- trunk/FACT++/gui/FactGui.h	(revision 11645)
+++ trunk/FACT++/gui/FactGui.h	(revision 11646)
@@ -2764,5 +2764,5 @@
     {
         const uint16_t isw = fThresholdIdx->value();
-        const uint16_t ihw = fPatchMapHW[isw];
+        const uint16_t ihw = isw<0 ? -1 : fPatchMapHW[isw];
 
         Dim::SendCommand("FTM_CONTROL/DISABLE_ALL_PATCHES_EXCEPT", ihw);
@@ -2774,5 +2774,5 @@
 
         const int32_t isw = fThresholdIdx->value();
-        const int32_t ihw = fPatchMapHW[isw];
+        const int32_t ihw = isw<0 ? -1 : fPatchMapHW[isw];
 
         const int32_t d[2] = { ihw, v };