diff --git a/pylot/core/io/phases.py b/pylot/core/io/phases.py
index c85d2727..3002680b 100644
--- a/pylot/core/io/phases.py
+++ b/pylot/core/io/phases.py
@@ -582,8 +582,6 @@ def writephases(arrivals, fformat, filename, parameter, eventinfo=None):
         fid = open("%s" % filename, 'w')
         # write header
         fid.write('%s, event %s \n' % (parameter.get('database'), parameter.get('eventID')))
-        errP = parameter.get('timeerrorsP')
-        errS = parameter.get('timeerrorsS')
         for key in arrivals:
             # P onsets
             if arrivals[key].has_key('P'):
diff --git a/pylot/core/pick/autopick.py b/pylot/core/pick/autopick.py
index 9e9e7857..1bb2527f 100644
--- a/pylot/core/pick/autopick.py
+++ b/pylot/core/pick/autopick.py
@@ -450,16 +450,19 @@ def autopickstation(wfstream, pickparam, verbose=False,
                 [SNRP, SNRPdB, Pnoiselevel] = getSNR(z_copy, tsnrz, mpickP)
 
                 # weight P-onset using symmetric error
-                if Perror <= timeerrorsP[0]:
-                    Pweight = 0
-                elif timeerrorsP[0] < Perror <= timeerrorsP[1]:
-                    Pweight = 1
-                elif timeerrorsP[1] < Perror <= timeerrorsP[2]:
-                    Pweight = 2
-                elif timeerrorsP[2] < Perror <= timeerrorsP[3]:
-                    Pweight = 3
-                elif Perror > timeerrorsP[3]:
+                if Perror == None:
                     Pweight = 4
+                else:
+                    if Perror <= timeerrorsP[0]:
+                        Pweight = 0
+                    elif timeerrorsP[0] < Perror <= timeerrorsP[1]:
+                        Pweight = 1
+                    elif timeerrorsP[1] < Perror <= timeerrorsP[2]:
+                        Pweight = 2
+                    elif timeerrorsP[2] < Perror <= timeerrorsP[3]:
+                        Pweight = 3
+                    elif Perror > timeerrorsP[3]:
+                        Pweight = 4
 
                 ##############################################################
                 # get first motion of P onset