diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7450b5ec..2b9de005 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,8 @@ CHANGELOG for FlatCAM beta
 - minor change for the FCComboBox UI element by setting its size policy as ignored so it will not expand the notebook when the name of one of its items is very long
 - added a protection on opening the tools database UI if the tools DB file is not loaded
 - fixed NCC Tool not working with the new changes; the check for not having complete isolation is just a Warning
+- fixed the sizePolicy for the FCComboBox widgets in the Preferences that holds the preprocessors
+- fixed issue with how the preamble / postamble GCode were inserted into the final GCode
 
 28.10.2020
 
diff --git a/appGUI/preferences/geometry/GeometryOptPrefGroupUI.py b/appGUI/preferences/geometry/GeometryOptPrefGroupUI.py
index 7ca13738..e3277e9b 100644
--- a/appGUI/preferences/geometry/GeometryOptPrefGroupUI.py
+++ b/appGUI/preferences/geometry/GeometryOptPrefGroupUI.py
@@ -259,6 +259,7 @@ class GeometryOptPrefGroupUI(OptionsGroupUI):
         )
         self.pp_geometry_name_cb = FCComboBox()
         self.pp_geometry_name_cb.setFocusPolicy(Qt.StrongFocus)
+        self.pp_geometry_name_cb.setSizePolicy(QtWidgets.QSizePolicy.MinimumExpanding, QtWidgets.QSizePolicy.Preferred)
 
         grid1.addWidget(pp_label, 13, 0)
         grid1.addWidget(self.pp_geometry_name_cb, 13, 1)
diff --git a/appGUI/preferences/tools/ToolsDrillPrefGroupUI.py b/appGUI/preferences/tools/ToolsDrillPrefGroupUI.py
index 810c28cf..0e941770 100644
--- a/appGUI/preferences/tools/ToolsDrillPrefGroupUI.py
+++ b/appGUI/preferences/tools/ToolsDrillPrefGroupUI.py
@@ -226,6 +226,7 @@ class ToolsDrillPrefGroupUI(OptionsGroupUI):
 
         self.pp_excellon_name_cb = FCComboBox()
         self.pp_excellon_name_cb.setFocusPolicy(Qt.StrongFocus)
+        self.pp_excellon_name_cb.setSizePolicy(QtWidgets.QSizePolicy.MinimumExpanding, QtWidgets.QSizePolicy.Preferred)
 
         grid0.addWidget(pp_excellon_label, 14, 0)
         grid0.addWidget(self.pp_excellon_name_cb, 14, 1, 1, 2)
diff --git a/appObjects/FlatCAMCNCJob.py b/appObjects/FlatCAMCNCJob.py
index 1555c34d..6efa49f6 100644
--- a/appObjects/FlatCAMCNCJob.py
+++ b/appObjects/FlatCAMCNCJob.py
@@ -188,8 +188,8 @@ class CNCJobObject(FlatCAMObj, CNCjob):
         self.mm = None
         self.mr = None
 
-        self.append_snippet = ''
         self.prepend_snippet = ''
+        self.append_snippet = ''
         self.gc_header = self.gcode_header()
         self.gc_start = ''
         self.gc_end = ''
@@ -532,7 +532,7 @@ class CNCJobObject(FlatCAMObj, CNCjob):
         self.append_snippet = self.app.defaults['cncjob_append']
         self.prepend_snippet = self.app.defaults['cncjob_prepend']
 
-        if self.append_snippet != '' or self.prepend_snippet:
+        if self.append_snippet != '' or self.prepend_snippet != '':
             self.ui.snippets_cb.set_value(True)
 
         # Fill form fields only on object create
@@ -661,8 +661,8 @@ class CNCJobObject(FlatCAMObj, CNCjob):
                 self.ui.sal_btn.show()
                 self.ui.sal_btn.setChecked(self.app.defaults["cncjob_al_status"])
 
-        preamble = self.append_snippet
-        postamble = self.prepend_snippet
+        preamble = self.prepend_snippet
+        postamble = self.append_snippet
         gc = self.export_gcode(preamble=preamble, postamble=postamble, to_file=True)
         self.source_file = gc.getvalue()
 
@@ -1950,8 +1950,8 @@ class CNCJobObject(FlatCAMObj, CNCjob):
 
         try:
             if self.ui.snippets_cb.get_value():
-                preamble = self.append_snippet
-                postamble = self.prepend_snippet
+                preamble = self.prepend_snippet
+                postamble = self.append_snippet
             gc = self.export_gcode(filename, preamble=preamble, postamble=postamble)
         except Exception as err:
             log.debug("CNCJobObject.export_gcode_handler() --> %s" % str(err))
@@ -1965,18 +1965,17 @@ class CNCJobObject(FlatCAMObj, CNCjob):
         self.app.file_saved.emit("gcode", filename)
         self.app.inform.emit('[success] %s: %s' % (_("File saved to"), filename))
 
-    def on_review_code_click(self, *args):
+    def on_review_code_click(self):
         """
         Handler activated by a button clicked when reviewing GCode.
 
-        :param args:
         :return:
         """
 
         self.app.proc_container.view.set_busy(_("Loading..."))
 
-        preamble = self.append_snippet
-        postamble = self.prepend_snippet
+        preamble = self.prepend_snippet
+        postamble = self.append_snippet
 
         gco = self.export_gcode(preamble=preamble, postamble=postamble, to_file=True)
         if gco == 'fail':