diff --git a/synda/sdt/sddaemon.py b/synda/sdt/sddaemon.py
index 6b84fee6..59983549 100755
--- a/synda/sdt/sddaemon.py
+++ b/synda/sdt/sddaemon.py
@@ -64,7 +64,7 @@ def main_loop(config_manager):
     try:
         sdtaskscheduler.event_loop(config_manager)
 
-    except SDException as e:
+    except Exception as e:
 
         level = preferences.log_verbosity_level
 
diff --git a/synda/sdt/sddatasetutils.py b/synda/sdt/sddatasetutils.py
index a88b3566..4f8cef26 100755
--- a/synda/sdt/sddatasetutils.py
+++ b/synda/sdt/sddatasetutils.py
@@ -27,7 +27,7 @@ def get_old_versions_datasets():
                 if not datasetVersions.is_version_higher_than_latest(d): # version is not higher than latest
                     # assert
                     if datasetVersions.is_most_recent_version_number(d): # should never occurs because of the previous tests
-                        raise SDException("SDSTAT-042","fatal error (version=%s,path_without_version=%s)"%(d.version,d.get_name_without_version()))
+                        raise SDException("SDSTAT-042","fatal error (version=%s,path_without_version=%s)"%(d.version,d.path_without_version()))
 
                     lst.append(d)
 
diff --git a/synda/sdt/sdenqueue.py b/synda/sdt/sdenqueue.py
index df3dc66b..322f7e5d 100755
--- a/synda/sdt/sdenqueue.py
+++ b/synda/sdt/sdenqueue.py
@@ -146,7 +146,12 @@ def keep_recent_datasets(datasets):
 
     for d in datasets:
 
-        if 'last_mode_date' in list(d.__dict__.keys()):
+        if not hasattr(d,'last_mod_date') or d.last_mod_date is None:
+            # probably imported from another database missing last_mod_date.
+            # But certainly it wasn't modified in the last 24 hours.
+            # And an interval calculation won't work with None.
+            pass
+        else:
             interval = sdtime.compute_time_delta(
                 d.last_mod_date,
                 sdtime.now(),
diff --git a/synda/sdt/sdfiledao.py b/synda/sdt/sdfiledao.py
index 79cf8765..95875e86 100755
--- a/synda/sdt/sdfiledao.py
+++ b/synda/sdt/sdfiledao.py
@@ -105,9 +105,14 @@ def get_file(file_functional_id,conn=sddb.conn):
     """
     t=None
 
-    c = conn.cursor()
-    c.execute("select * from file where file_functional_id = ?", (file_functional_id,))
-    rs=c.fetchone()
+    try:
+        c = conn.cursor()
+        c.execute("select * from file where file_functional_id = ?", (file_functional_id,))
+        rs=c.fetchone()
+    except:
+        sdlog.info("SDFILDAO-100","get_file exception %s, file_functional_id %s" %
+                   (e, file_functional_id) )
+        raise e
     if rs is not None:
         t=sdsqlutils.get_object_from_resultset(rs,File)
     c.close()
diff --git a/synda/sdt/sdhistory.py b/synda/sdt/sdhistory.py
index e4b3fb0c..0d860713 100755
--- a/synda/sdt/sdhistory.py
+++ b/synda/sdt/sdhistory.py
@@ -52,7 +52,7 @@ def file_changed_since_last_run(selection_file, action):
     previous_run = get_previous_run(selection_filename, action)
     previous_checksum = previous_run['selection_file_checksum']
 
-    return previous_checksum == current_checksum
+    return previous_checksum != current_checksum
 
 
 def add_history_line(action=None, selection_file=None, insertion_group_id=None, crea_date=None):
diff --git a/synda/sdt/sdmyproxy.py b/synda/sdt/sdmyproxy.py
index 909dbea0..cedba59c 100755
--- a/synda/sdt/sdmyproxy.py
+++ b/synda/sdt/sdmyproxy.py
@@ -187,7 +187,7 @@ def renew_certificate(host, port, username, password):
 
     parser = argparse.ArgumentParser()
 
-    parser.add_argument('--host', '-h', default='pcmdi9.llnl.gov')
+    parser.add_argument('--host', '-h', default='esgf-node.llnl.gov')
     parser.add_argument('--port', '-p', type=int, default=7512)
     parser.add_argument(
         '--force_renew_certificate',
@@ -206,7 +206,7 @@ def renew_certificate(host, port, username, password):
     args = parser.parse_args()
 
     run(
-        args.hostname,
+        args.host,
         args.port,
         args.username,
         args.force_renew_certificate,