Hoping this will work *knocks on wood*

celery/pool.py

@@ -12,6 +12,7 @@ from multiprocessing.pool import Pool, worker
 from celery.datastructures import ExceptionInfo
 from celery.utils import gen_unique_id
 from functools import partial as curry
+from operator import isNumberType
 
 
 def pid_is_dead(pid):
@@ -65,12 +66,6 @@ def process_is_dead(process):
 
     """
 
-    # Make sure PID is an integer (no idea why this happens).
-    try:
-        int(process.pid)
-    except (TypeError, ValueError):
-        return True
-
     # Try to see if the process is actually running,
     # and reap zombie proceses while we're at it.
 
@@ -111,10 +106,13 @@ class DynamicPool(Pool):
         w = self.Process(target=worker,
                          args=(self._inqueue, self._outqueue,
                                self._initializer, self._initargs))
-        self._pool.append(w)
         w.name = w.name.replace("Process", "PoolWorker")
         w.daemon = True
         w.start()
+        self._pool.append(w)
+        self.logger.debug(
+            "DynamicPool: Started pool worker %s (PID: %s, Poolsize: %d)" %(
+                w.name, w.pid, len(self._pool))
 
     def grow(self, size=1):
         """Add workers to the pool.
@@ -145,15 +143,24 @@ class DynamicPool(Pool):
         """
         dead, alive = [], []
         for process in self._pool:
-            if process and process.pid:
+            if process and process.pid and isNumberType(process.pid):
                 dest = dead if self._is_dead(process) else alive
                 dest.append(process)
         return dead, alive 
 
     def replace_dead_workers(self):
-        """Replace dead workers in the pool by spawning new ones."""
-        dead, self._pool = self._bring_out_the_dead()
-        self.grow(self._size if len(dead) > self._size else len(dead))
+        """Replace dead workers in the pool by spawning new ones.
+        
+        :returns: number of dead processes replaced, or ``None`` if all
+            processes are alive and running.
+
+        """
+        dead, alive = self._bring_out_the_dead()
+        if dead:
+            dead_count = len(dead)
+            self._pool = alive
+            self.grow(self._size if dead_count > self._size else dead_count)
+            return dead_count
 
 
 class TaskPool(object):