diff --git a/CHANGES b/CHANGES
index fa9b14c..67feec3 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,11 @@
 CHANGES
 -------
 
+# v0.6.33
+
+- added ambiguity parsing for normal position reports
+  (fixes the unexpected exception)
+
 # v0.6.32
 
 - sendall() method to IS, allows sending of packets
diff --git a/aprslib/__init__.py b/aprslib/__init__.py
index 168b9f3..b3b9dfb 100644
--- a/aprslib/__init__.py
+++ b/aprslib/__init__.py
@@ -25,16 +25,19 @@ Currently the library provides facilities to:
 
 # handles reloading
 if 'IS' in globals():
-    modules = __import__('sys').modules
-    for m in modules.keys():
-        if m[:len(__name__)+1] == "%s." % __name__:
-            del modules[m]
+    MODULES = __import__('sys').modules
+    for M in MODULES.keys():
+        if M[:len(__name__)+1] == "%s." % __name__:
+            del MODULES[M]
+
+    del MODULES
+    del M
 
 from datetime import date as _date
 __date__ = str(_date.today())
 del _date
 
-__version__ = "0.6.32"
+__version__ = "0.6.33"
 __author__ = "Rossen Georgiev"
 __all__ = ['IS', 'parse', 'passcode']
 
diff --git a/aprslib/parse.py b/aprslib/parse.py
index a45f1fd..f55445a 100644
--- a/aprslib/parse.py
+++ b/aprslib/parse.py
@@ -818,7 +818,17 @@ def _parse_normal(body):
             body
         ) = match[0]
 
-        # TODO: position ambiguity
+        # position ambiguity
+        posambiguity = lat_min.count(' ')
+        parsed.update({'posambiguity': posambiguity})
+
+        # we center the position inside the ambiguity box
+        if posambiguity >= 4:
+            lat_min = "30"
+            lon_min = "30"
+        else:
+            lat_min = lat_min.replace(' ', '5', 1)
+            lon_min = lon_min.replace(' ', '5', 1)
 
         # validate longitude and latitude
 
@@ -839,7 +849,6 @@ def _parse_normal(body):
         """
 
         # convert coordinates from DDMM.MM to decimal
-
         latitude = int(lat_deg) + (float(lat_min) / 60.0)
         longitude = int(lon_deg) + (float(lon_min) / 60.0)