diff --git a/pbxproj/pbxextensions/ProjectFiles.py b/pbxproj/pbxextensions/ProjectFiles.py
old mode 100644
new mode 100755
index f55cd0cf..21eb4adc
--- a/pbxproj/pbxextensions/ProjectFiles.py
+++ b/pbxproj/pbxextensions/ProjectFiles.py
@@ -325,6 +325,11 @@ def _create_build_files(self, file_ref, attributes, build_phases):
         results = []
         # create the build file and add it to the phase
         for target_build_phase in build_phases:
+            # check to see if we already have a PBXBuildFile for this file_ref in this phase, if so
+            # don't create another one
+            if any(str(self.objects[str(build_file)].fileRef) == file_ref.get_id() for build_file in target_build_phase.files):
+                continue
+
             build_file = PBXBuildFile.create(file_ref, attributes)
             self.objects[build_file.get_id()] = build_file
             target_build_phase.add_build_file(build_file)
diff --git a/pbxproj/pbxsections/PBXGroup.py b/pbxproj/pbxsections/PBXGroup.py
old mode 100644
new mode 100755
index b3f526e4..1de06dfa
--- a/pbxproj/pbxsections/PBXGroup.py
+++ b/pbxproj/pbxsections/PBXGroup.py
@@ -1,5 +1,6 @@
 from pbxproj.PBXGenericObject import *
 from pbxproj.pbxsections import *
+from pbxproj.pbxsections.PBXVariantGroup import *
 
 
 class PBXGroup(PBXGenericObject):
@@ -44,7 +45,7 @@ def has_child(self, child):
 
     def add_child(self, child):
         # if it's not the right type of children for the group
-        if not isinstance(child, PBXGroup) and not isinstance(child, PBXFileReference):
+        if not isinstance(child, PBXGroup) and not isinstance(child, PBXFileReference) and not isinstance(child, PBXVariantGroup):
             return False
 
         self.children.append(child.get_id())