diff --git a/docs/config.rst b/docs/config.rst
index 3789990..fe90c6a 100644
--- a/docs/config.rst
+++ b/docs/config.rst
@@ -609,8 +609,10 @@ Rendering
 .. _crop:
 
 ``crop``
-    You can use this to render a small subset of your map, instead of the entire
-    thing. The format is (min x, min z, max x, max z).
+    You can use this to render one or more small subsets of your map. The format
+    of an individual crop zone is (min x, min z, max x, max z); if you wish to
+    specify multiple crop zones, you may do so by specifying a list of crop zones,
+    i.e. [(min x1, min z1, max x1, max z1), (min x2, min z2, max x2, max z2)]
 
     The coordinates are block coordinates. The same you get with the debug menu
     in-game and the coordinates shown when you view a map.
@@ -623,6 +625,14 @@ Rendering
                 'crop': (-500, -500, 500, 500),
         }
 
+    Example that renders two 500 by 500 squares of land:
+
+        renders['myrender'] = {
+                'world': 'myworld',
+                'title': "Multi cropped Example",
+                'crop': [(-500, -500, 0, 0), (0, 0, 500, 500)]
+        }
+
     This option performs a similar function to the old ``--regionlist`` option
     (which no longer exists). It is useful for example if someone has wandered
     really far off and made your map too large. You can set the crop for the
@@ -830,7 +840,6 @@ Other HTML/JS output options
        markers and signs on our map, you must also run the genPO script.  See
        the :doc:`Signs and markers<signs>` section for more details and documenation.
 
-
     **Default:** ``[]`` (an empty list)
 
 
diff --git a/overviewer.py b/overviewer.py
index 43bd44f..83bb6de 100755
--- a/overviewer.py
+++ b/overviewer.py
@@ -488,16 +488,20 @@ dir but you forgot to put quotes around the directory, since it contains spaces.
         # regionset cache pulls from the same underlying cache object.
         rset = world.CachedRegionSet(rset, caches)
 
-        # If a crop is requested, wrap the regionset here
-        if "crop" in render:
-            rset = world.CroppedRegionSet(rset, *render['crop'])
-
         # If this is to be a rotated regionset, wrap it in a RotatedRegionSet
         # object
         if (render['northdirection'] > 0):
             rset = world.RotatedRegionSet(rset, render['northdirection'])
         logging.debug("Using RegionSet %r", rset)
 
+        # If a crop is requested, wrap the regionset here
+        if "crop" in render:
+            rsets = []
+            for zone in render['crop']:
+                rsets.append(world.CroppedRegionSet(rset, *zone))
+        else:
+            rsets = [rset]
+
         ###############################
         # Do the final prep and create the TileSet object
 
@@ -508,8 +512,9 @@ dir but you forgot to put quotes around the directory, since it contains spaces.
         render['name'] = render_name # perhaps a hack. This is stored here for the asset manager
         tileSetOpts = util.dict_subset(render, ["name", "imgformat", "renderchecks", "rerenderprob", "bgcolor", "defaultzoom", "imgquality", "optimizeimg", "rendermode", "worldname_orig", "title", "dimension", "changelist", "showspawn", "overlay", "base", "poititle", "maxzoom", "showlocationmarker", "minzoom"])
         tileSetOpts.update({"spawn": w.find_true_spawn()}) # TODO find a better way to do this
-        tset = tileset.TileSet(w, rset, assetMrg, tex, tileSetOpts, tileset_dir)
-        tilesets.append(tset)
+        for rset in rsets:
+            tset = tileset.TileSet(w, rset, assetMrg, tex, tileSetOpts, tileset_dir)
+            tilesets.append(tset)
 
     # Do tileset preprocessing here, before we start dispatching jobs
     logging.info("Preprocessing...")
diff --git a/overviewer_core/files.py b/overviewer_core/files.py
index ca6d8a6..15647fe 100644
--- a/overviewer_core/files.py
+++ b/overviewer_core/files.py
@@ -19,6 +19,7 @@ import tempfile
 import shutil
 import logging
 import stat
+import errno
 
 default_caps = {"chmod_works": True, "rename_works": True}
 
@@ -150,6 +151,20 @@ class FileReplacer(object):
             else:
                 # copy permission bits, if needed
                 if self.caps.get("chmod_works") and os.path.exists(self.destname):
-                    shutil.copymode(self.destname, self.tmpname)
+                    try:
+                        shutil.copymode(self.destname, self.tmpname)
+                    except OSError, e:
+                        # Ignore errno ENOENT: file does not exist. Due to a race
+                        # condition, two processes could conceivably try and update
+                        # the same temp file at the same time
+                        if e.errno != errno.ENOENT:
+                            raise
                 # atomic rename into place
-                os.rename(self.tmpname, self.destname)
+                try:
+                    os.rename(self.tmpname, self.destname)
+                except OSError, e:
+                    # Ignore errno ENOENT: file does not exist. Due to a race
+                    # condition, two processes could conceivably try and update
+                    # the same temp file at the same time
+                    if e.errno != errno.ENOENT:
+                        raise
diff --git a/overviewer_core/settingsValidators.py b/overviewer_core/settingsValidators.py
index 29553a7..2b3d28f 100644
--- a/overviewer_core/settingsValidators.py
+++ b/overviewer_core/settingsValidators.py
@@ -225,15 +225,23 @@ def validateOutputDir(d):
     return expand_path(d)
 
 def validateCrop(value):
-    if len(value) != 4:
-        raise ValidationException("The value for the 'crop' setting must be a tuple of length 4")
-    a, b, c, d = tuple(int(x) for x in value)
-
-    if a >= c:
-        a, c = c, a
-    if b >= d:
-        b, d = d, b
-    return (a, b, c, d)
+    if not isinstance(value, list):
+        value = [value]
+        
+    cropZones = []
+    for zone in value:
+        if not isinstance(zone, tuple) or len(zone) != 4:
+            raise ValidationException("The value for the 'crop' setting must be an array of tuples of length 4")
+        a, b, c, d = tuple(int(x) for x in zone)
+    
+        if a >= c:
+            a, c = c, a
+        if b >= d:
+            b, d = d, b
+        
+        cropZones.append((a, b, c, d))
+        
+    return cropZones
 
 def validateObserver(observer):
     if all(map(lambda m: hasattr(observer, m), ['start', 'add', 'update', 'finish'])):
diff --git a/overviewer_core/tileset.py b/overviewer_core/tileset.py
index 0d90446..b744d6e 100644
--- a/overviewer_core/tileset.py
+++ b/overviewer_core/tileset.py
@@ -947,7 +947,14 @@ class TileSet(object):
             if self.options['optimizeimg']:
                 optimize_image(tmppath, imgformat, self.options['optimizeimg'])
 
-            os.utime(tmppath, (max_mtime, max_mtime))
+            try:
+                os.utime(tmppath, (max_mtime, max_mtime))
+            except OSError, e:
+                # Ignore errno ENOENT: file does not exist. Due to a race
+                # condition, two processes could conceivably try and update
+                # the same temp file at the same time
+                if e.errno != errno.ENOENT:
+                    raise
 
     def _render_rendertile(self, tile):
         """Renders the given render-tile.