diff --git a/README.md b/README.md
index a2b96e38..4445109e 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,11 @@ CAD program, and create G-Code for Isolation routing.
 
 =================================================
 
+7.09.2019
+
+- replaced setFixedWidth calls with setMinimumWidth
+- recoded the camlib.Geometry.isolation_geometry() function
+
 6.08.2019
 
 - fixed bug that crashed the app after creating a new geometry, if a new object is loaded and the new geometry is deleted and then trying to select the just loaded new object
@@ -16,7 +21,6 @@ CAD program, and create G-Code for Isolation routing.
 - fixed issue in the isolation function, if the isolation can't be done there will be generated no Geometry object 
 - some minor UI changes
 - strings added and translations updated
-- replaced setFixedWidth calls with setMinimumWidth
 
 5.08.2019
 
diff --git a/camlib.py b/camlib.py
index 10315d96..ae937b58 100644
--- a/camlib.py
+++ b/camlib.py
@@ -555,19 +555,21 @@ class Geometry(object):
                 geo_iso = self.follow_geometry
             else:
                 if corner is None:
-                    if type(self.solid_geometry) is list and len(self.solid_geometry) == 1:
-                        geo_iso = self.solid_geometry[0].buffer(offset, int(int(self.geo_steps_per_circle) / 4))
-                    else:
+                    try:
+                        __ = iter(self.solid_geometry)
                         for el in self.solid_geometry:
                             geo_iso.append(el.buffer(offset, int(int(self.geo_steps_per_circle) / 4)))
+                    except TypeError:
+                        geo_iso = self.solid_geometry.buffer(offset, int(int(self.geo_steps_per_circle) / 4))
                 else:
-                    if type(self.solid_geometry) is list and len(self.solid_geometry) == 1:
-                        geo_iso = self.solid_geometry.buffer[0](offset, int(int(self.geo_steps_per_circle) / 4),
-                                                                join_style=corner)
-                    else:
+                    try:
+                        __ = iter(self.solid_geometry)
                         for el in self.solid_geometry:
                             geo_iso.append(el.buffer(offset, int(int(self.geo_steps_per_circle) / 4),
                                                      join_style=corner))
+                    except TypeError:
+                        geo_iso = self.solid_geometry.buffer(offset, int(int(self.geo_steps_per_circle) / 4),
+                                                             join_style=corner)
 
         # end of replaced block
         if follow: