diff --git a/libs/core/pxt.cpp b/libs/core/pxt.cpp
index 639b8da0..99e4f0f7 100644
--- a/libs/core/pxt.cpp
+++ b/libs/core/pxt.cpp
@@ -152,7 +152,6 @@ namespace pxt {
       {
           return data[i];          
       }
-      error(ERR_OUT_OF_BOUNDS);
       return Segment::DefaultValue;
     }
 
@@ -275,7 +274,6 @@ namespace pxt {
         --length;
         return value;
       }
-      error(ERR_OUT_OF_BOUNDS);      
       return Segment::DefaultValue;
     }
 
@@ -304,7 +302,6 @@ namespace pxt {
 #endif  
         return ret;
       }
-      error(ERR_OUT_OF_BOUNDS);
       return Segment::DefaultValue;
     }
 
@@ -387,29 +384,16 @@ namespace pxt {
 
     uint32_t RefCollection::getAt(int i) 
     {
-      if (head.isValidIndex(i)) 
+      uint32_t tmp = head.get(i);
+      if (isRef())
       {
-        uint32_t tmp = head.get(i);
-        if (isRef())
-        {
-          incr(tmp);
-        }
-        return tmp;
-      }
-      else 
-      {
-        error(ERR_OUT_OF_BOUNDS);
-        return 0;
+        incr(tmp);
       }
+      return tmp;
     }
 
     uint32_t RefCollection::removeAt(int i) 
     {
-      if (!head.isValidIndex((uint32_t)i))
-      {
-        error(ERR_OUT_OF_BOUNDS);
-        return 0;
-      }
       if (isRef())
       {
         decr(head.get(i));
@@ -419,18 +403,11 @@ namespace pxt {
 
     void RefCollection::insertAt(int i, uint32_t value) 
     {
-      if (((uint32_t)i) < length())
+      head.insert(i, value);
+      if (isRef())
       {
-        head.insert(i, value);
-        if (isRef())
-        {
-          incr(value);
-        } 
-      }
-      else
-      {
-        error(ERR_OUT_OF_BOUNDS);
-      }
+        incr(value);
+      } 
     }
 
     void RefCollection::setAt(int i, uint32_t value)