diff --git a/pyqtgraph/multiprocess/processes.py b/pyqtgraph/multiprocess/processes.py
index a121487b..c7e4a80c 100644
--- a/pyqtgraph/multiprocess/processes.py
+++ b/pyqtgraph/multiprocess/processes.py
@@ -156,14 +156,14 @@ class Process(RemoteEventHandler):
                 time.sleep(0.05)
         self.debugMsg('Child process exited. (%d)' % self.proc.returncode)
 
-    def debugMsg(self, msg):
+    def debugMsg(self, msg, *args):
         if hasattr(self, '_stdoutForwarder'):
             ## Lock output from subprocess to make sure we do not get line collisions
             with self._stdoutForwarder.lock:
                 with self._stderrForwarder.lock:
-                    RemoteEventHandler.debugMsg(self, msg)
+                    RemoteEventHandler.debugMsg(self, msg, *args)
         else:
-            RemoteEventHandler.debugMsg(self, msg)
+            RemoteEventHandler.debugMsg(self, msg, *args)
 
         
 def startEventLoop(name, port, authkey, ppid, debug=False):
diff --git a/pyqtgraph/multiprocess/remoteproxy.py b/pyqtgraph/multiprocess/remoteproxy.py
index 4f484b74..66db1221 100644
--- a/pyqtgraph/multiprocess/remoteproxy.py
+++ b/pyqtgraph/multiprocess/remoteproxy.py
@@ -88,10 +88,10 @@ class RemoteEventHandler(object):
             print(pid, cls.handlers)
             raise
     
-    def debugMsg(self, msg):
+    def debugMsg(self, msg, *args):
         if not self.debug:
             return
-        cprint.cout(self.debug, "[%d] %s\n" % (os.getpid(), str(msg)), -1) 
+        cprint.cout(self.debug, "[%d] %s\n" % (os.getpid(), str(msg)%args), -1) 
     
     def getProxyOption(self, opt):
         with self.optsLock:
@@ -145,7 +145,7 @@ class RemoteEventHandler(object):
                     sys.excepthook(*sys.exc_info())
                     
             if numProcessed > 0:
-                self.debugMsg('processRequests: finished %d requests' % numProcessed)
+                self.debugMsg('processRequests: finished %d requests', numProcessed)
             return numProcessed
     
     def handleRequest(self):
@@ -166,15 +166,15 @@ class RemoteEventHandler(object):
                     self.debugMsg('  handleRequest: got IOError 4 from recv; try again.')
                     continue
                 else:
-                    self.debugMsg('  handleRequest: got IOError %d from recv (%s); raise ClosedError.' % (err.errno, err.strerror))
+                    self.debugMsg('  handleRequest: got IOError %d from recv (%s); raise ClosedError.', err.errno, err.strerror)
                     raise ClosedError()
         
-        self.debugMsg("  handleRequest: received %s %s" % (str(cmd), str(reqId)))
+        self.debugMsg("  handleRequest: received %s %s", cmd, reqId)
             
         ## read byte messages following the main request
         byteData = []
         if nByteMsgs > 0:
-            self.debugMsg("    handleRequest: reading %d byte messages" % nByteMsgs)
+            self.debugMsg("    handleRequest: reading %d byte messages", nByteMsgs)
         for i in range(nByteMsgs):
             while True:
                 try:
@@ -199,7 +199,7 @@ class RemoteEventHandler(object):
                               ## (this is already a return from a previous request)
             
             opts = pickle.loads(optStr)
-            self.debugMsg("    handleRequest: id=%s opts=%s" % (str(reqId), str(opts)))
+            self.debugMsg("    handleRequest: id=%s opts=%s", reqId, opts)
             #print os.getpid(), "received request:", cmd, reqId, opts
             returnType = opts.get('returnType', 'auto')
             
@@ -279,7 +279,7 @@ class RemoteEventHandler(object):
             
         if reqId is not None:
             if exc is None:
-                self.debugMsg("    handleRequest: sending return value for %d: %s" % (reqId, str(result))) 
+                self.debugMsg("    handleRequest: sending return value for %d: %s", reqId, result) 
                 #print "returnValue:", returnValue, result
                 if returnType == 'auto':
                     with self.optsLock:
@@ -294,7 +294,7 @@ class RemoteEventHandler(object):
                     sys.excepthook(*sys.exc_info())
                     self.replyError(reqId, *sys.exc_info())
             else:
-                self.debugMsg("    handleRequest: returning exception for %d" % reqId) 
+                self.debugMsg("    handleRequest: returning exception for %d", reqId) 
                 self.replyError(reqId, *exc)
                     
         elif exc is not None:
@@ -443,16 +443,16 @@ class RemoteEventHandler(object):
                 
             ## Send primary request
             request = (request, reqId, nByteMsgs, optStr)
-            self.debugMsg('send request: cmd=%s nByteMsgs=%d id=%s opts=%s' % (str(request[0]), nByteMsgs, str(reqId), str(opts)))
+            self.debugMsg('send request: cmd=%s nByteMsgs=%d id=%s opts=%s', request[0], nByteMsgs, reqId, opts)
             self.conn.send(request)
             
             ## follow up by sending byte messages
             if byteData is not None:
                 for obj in byteData:  ## Remote process _must_ be prepared to read the same number of byte messages!
                     self.conn.send_bytes(obj)
-                self.debugMsg('  sent %d byte messages' % len(byteData))
+                self.debugMsg('  sent %d byte messages', len(byteData))
             
-            self.debugMsg('  call sync: %s' % callSync)
+            self.debugMsg('  call sync: %s', callSync)
             if callSync == 'off':
                 return
             
@@ -572,7 +572,7 @@ class RemoteEventHandler(object):
             
         try:
             self.send(request='del', opts=dict(proxyId=proxyId), callSync='off')
-        except IOError:  ## if remote process has closed down, there is no need to send delete requests anymore
+        except ClosedError:  ## if remote process has closed down, there is no need to send delete requests anymore
             pass
 
     def transfer(self, obj, **kwds):
@@ -786,6 +786,7 @@ class ObjectProxy(object):
             'returnType': None,    ## 'proxy', 'value', 'auto', None
             'deferGetattr': None,  ## True, False, None
             'noProxyTypes': None,  ## list of types to send by value instead of by proxy
+            'autoProxy': None,
         }
         
         self.__dict__['_handler'] = RemoteEventHandler.getHandler(processId)
@@ -839,6 +840,9 @@ class ObjectProxy(object):
                        sent to the remote process.
         =============  =============================================================
         """
+        for k in kwds:
+            if k not in self._proxyOptions:
+                raise KeyError("Unrecognized proxy option '%s'" % k)
         self._proxyOptions.update(kwds)
     
     def _getValue(self):