diff -r fe71a67b8cbc rpy/rinterface/rinterface.c
--- a/rpy/rinterface/rinterface.c	Sat Feb 07 23:35:29 2009 -0800
+++ b/rpy/rinterface/rinterface.c	Sat Feb 07 23:44:10 2009 -0800
@@ -635,15 +635,19 @@
     return NULL;
   }
   embeddedR_setlock();
+  // R_ProcessEvents is only defined on Win32 and Aqua, and on Aqua it's
+  // effectively a no-op. Most R code that calls R_ProcessEvents therefore
+  // guards it in exactly this way:
+#ifdef Win32
   /* Can the call to R_ProcessEvents somehow fail ? */
   R_ProcessEvents();
+#endif // Win32
   embeddedR_freelock();
   Py_INCREF(Py_None);
   return Py_None;
 }
 PyDoc_STRVAR(EmbeddedR_ProcessEvents_doc,
-             "Process R events. This function is a simple wrapper around R_ProcessEvents.");
-
+             "Process R events. This function is a simple wrapper around R_ProcessEvents. (NB: this has no effect unless you are running Windows.)");
 
 static PyObject* EmbeddedR_init(PyObject *self) 
 {