diff --git a/gridmap/job.py b/gridmap/job.py
index 5e0d01e..9581d03 100644
--- a/gridmap/job.py
+++ b/gridmap/job.py
@@ -63,8 +63,9 @@
 from gridmap.runner import _heart_beat
 
 if DRMAA_PRESENT:
-    from drmaa import (InvalidJobException, JobControlAction,
-                       JOB_IDS_SESSION_ALL, Session)
+    from drmaa import (ExitTimeoutException, InvalidJobException,
+                       JobControlAction, JOB_IDS_SESSION_ALL, Session,
+                       TIMEOUT_NO_WAIT)
 
 # Python 2.x backward compatibility
 if sys.version_info < (3, 0):
@@ -274,7 +275,7 @@ def __init__(self, temp_dir='/scratch'):
         # uninitialized field (set in check method)
         self.jobs = []
         self.ids = []
-        self.session_id = -1
+        self.session_id = None
         self.id_to_job = {}
 
     def __enter__(self):
@@ -291,18 +292,27 @@ def __exit__(self, exc_type, exc_value, exc_tb):
         # Always close socket
         self.socket.close()
 
-        # If we encounter an exception, try to kill all jobs
-        if exc_type is not None:
-            self.logger.info('Encountered %s, so killing all jobs.',
-                             exc_type.__name__)
+        # Clean up if we have a valid session
+        if self.session_id is not None:
             with Session(self.session_id) as session:
-                # try to kill off all old jobs
+                # If we encounter an exception, kill all jobs
+                if exc_type is not None:
+                    self.logger.info('Encountered %s, so killing all jobs.',
+                                     exc_type.__name__)
+                    # try to kill off all old jobs
+                    try:
+                        session.control(JOB_IDS_SESSION_ALL,
+                                        JobControlAction.TERMINATE)
+                    except InvalidJobException:
+                        self.logger.debug("Could not kill all jobs for " +
+                                          "session.", exc_info=True)
+
+                # Get rid of job info to prevent memory leak
                 try:
-                    session.control(JOB_IDS_SESSION_ALL,
-                                    JobControlAction.TERMINATE)
-                except InvalidJobException:
-                    self.logger.debug("Could not kill all jobs for session.",
-                                      exc_info=True)
+                    session.synchronize([JOB_IDS_SESSION_ALL], TIMEOUT_NO_WAIT,
+                                        dispose=True)
+                except ExitTimeoutException:
+                    pass
 
     def check(self, session_id, jobs):
         """
@@ -316,9 +326,10 @@ def check(self, session_id, jobs):
         self.session_id = session_id
 
         # determines in which interval to check if jobs are alive
+        self.logger.debug('Starting local hearbeat')
         local_heart = multiprocessing.Process(target=_heart_beat,
                                               args=(-1, self.home_address, -1,
-                                                   "", CHECK_FREQUENCY))
+                                                    "", CHECK_FREQUENCY))
         local_heart.start()
         try:
             self.logger.debug("Starting ZMQ event loop")
@@ -432,6 +443,8 @@ def check_if_alive(self):
 
             # could have been an exception, we check right away
             elif isinstance(job.ret, Exception):
+                job.cause_of_death = 'exception'
+
                 # Send error email, in addition to raising and logging exception
                 send_error_mail(job)
 
diff --git a/gridmap/version.py b/gridmap/version.py
index fc20c68..de9b760 100644
--- a/gridmap/version.py
+++ b/gridmap/version.py
@@ -28,5 +28,5 @@
 :organization: ETS
 '''
 
-__version__ = '0.12.1'
+__version__ = '0.12.2'
 VERSION = tuple(int(x) for x in __version__.split('.'))