diff --git a/Code/Mantid/Testing/SystemTests/tests/analysis/ISIS_LETReduction.py b/Code/Mantid/Testing/SystemTests/tests/analysis/ISIS_LETReduction.py
index 4ef143cfc20903665693fe4017a837997819cc7a..dec441014302f979c751586c03030a5d952ea6ee 100644
--- a/Code/Mantid/Testing/SystemTests/tests/analysis/ISIS_LETReduction.py
+++ b/Code/Mantid/Testing/SystemTests/tests/analysis/ISIS_LETReduction.py
@@ -1,6 +1,6 @@
-""" Sample LET reduction script """ 
+""" Sample LET reduction script """
 import os
-os.environ["PATH"] = r"c:/Mantid/Code/builds/br_master/bin/Release;"+os.environ["PATH"]
+#os.environ["PATH"] = r"c:/Mantid/Code/builds/br_master/bin/Release;"+os.environ["PATH"]
 
 
 from Direct.ReductionWrapper import *
@@ -291,4 +291,4 @@ if __name__=="__main__":
     #if not rez:
     #   raise RuntimeError("validation failed with error: {0}".format(mess))
     #else:
-    #   print "ALL Fine" 
\ No newline at end of file
+    #   print "ALL Fine"
\ No newline at end of file
diff --git a/Code/Mantid/scripts/Inelastic/Direct/DirectEnergyConversion.py b/Code/Mantid/scripts/Inelastic/Direct/DirectEnergyConversion.py
index 1ba99869950964ca60b6fbe3e986c7f152d94db2..5213436b0e0a7c825a6e9541f35ade5d9805fe17 100644
--- a/Code/Mantid/scripts/Inelastic/Direct/DirectEnergyConversion.py
+++ b/Code/Mantid/scripts/Inelastic/Direct/DirectEnergyConversion.py
@@ -623,7 +623,7 @@ class DirectEnergyConversion(object):
 
         data_ws = data_run.get_workspace()
         monitor_ws = data_run.get_monitors_ws()
-        if not monitor_ws:
+        if monitor_ws is None:
            raise RuntimeError("Can not find monitors workspace for workspace {0}, run N{1}".\
                  format(data_ws.name(),data_ws.getRunNumber()))
         separate_monitors = data_run.is_monws_separate()
diff --git a/Code/Mantid/scripts/Inelastic/Direct/RunDescriptor.py b/Code/Mantid/scripts/Inelastic/Direct/RunDescriptor.py
index 36b63151e40696faddfcde20bc64c7c9963dd3b0..474f6c89ce2c551e2b9d3a5b2319414a0086c17f 100644
--- a/Code/Mantid/scripts/Inelastic/Direct/RunDescriptor.py
+++ b/Code/Mantid/scripts/Inelastic/Direct/RunDescriptor.py
@@ -410,13 +410,20 @@ class RunDescriptor(PropDescriptor):
                 self._clear_all()
                 # clear all would invalidate run number and workspace number
                 self._run_number = int(run_number)
+                self._ws_name = self._build_ws_name()
                 self._run_file_path = file_path
                 self._fext = fext
-                self._ws_name = self._build_ws_name()
             else: # nothing to do, there is workspace, which corresponds to this run number
                 # and it may be already loaded (may be not).  Just nullify run list
                                  # in case of previous workspace name came from a list.
                 self._run_list = None
+                if not self._ws_name in mtd:
+                    # Change existing file path and file extension if alternatives are provided
+                    if len(file_path)>0:
+                        self._run_file_path = file_path
+                    if not fext is None:
+                        self._fext = fext
+
 
 
 #--------------------------------------------------------------------------------------------------------------------