diff --git a/lib/bb/ui/crumbs/builder.py b/lib/bb/ui/crumbs/builder.py
index eeaa278..b651643 100755
--- a/lib/bb/ui/crumbs/builder.py
+++ b/lib/bb/ui/crumbs/builder.py
@@ -493,7 +493,7 @@ class Builder(gtk.Window):
             response = dialog.run()
             dialog.destroy()
         self.handler.clear_busy()
-        self.configuration.curr_mach = None
+        self.configuration.curr_mach = ""
         self.image_configuration_page.switch_machine_combo()
         self.switch_page(self.MACHINE_SELECTION)
 
@@ -826,7 +826,7 @@ class Builder(gtk.Window):
             self.configuration = dialog.configuration
             # DO reparse recipes
             if dialog.settings_changed:
-                if self.configuration.curr_mach == "":
+                if not self.configuration.curr_mach:
                     self.switch_page(self.MACHINE_SELECTION)
                 else:
                     self.switch_page(self.RCPPKGINFO_POPULATING)
diff --git a/lib/bb/ui/crumbs/hobeventhandler.py b/lib/bb/ui/crumbs/hobeventhandler.py
index e5e0b42..6efb9b0 100644
--- a/lib/bb/ui/crumbs/hobeventhandler.py
+++ b/lib/bb/ui/crumbs/hobeventhandler.py
@@ -258,7 +258,8 @@ class HobHandler(gobject.GObject):
         self.server.runCommand(["setVariable", "BBLAYERS", " ".join(bblayers)])
 
     def set_machine(self, machine):
-        self.server.runCommand(["setVariable", "MACHINE", machine])
+        if machine:
+            self.server.runCommand(["setVariable", "MACHINE", machine])
 
     def set_sdk_machine(self, sdk_machine):
         self.server.runCommand(["setVariable", "SDKMACHINE", sdk_machine])