diff --git a/direct/src/plugin/p3dInstance.cxx b/direct/src/plugin/p3dInstance.cxx
index 3871dfa622..8c4b27ab69 100644
--- a/direct/src/plugin/p3dInstance.cxx
+++ b/direct/src/plugin/p3dInstance.cxx
@@ -153,7 +153,9 @@ set_property(const string &property_name, const string &value) {
 ////////////////////////////////////////////////////////////////////
 bool P3DInstance::
 has_request() {
+  nout << "has_request called, getting lock\n" << flush;
   ACQUIRE_LOCK(_request_lock);
+  nout << "got lock\n" << flush;
   bool any_requests = !_pending_requests.empty();
   RELEASE_LOCK(_request_lock);
   return any_requests;
@@ -202,10 +204,11 @@ add_request(P3D_request *request) {
   RELEASE_LOCK(_request_lock);
 
   // Asynchronous notification for anyone who cares.
-  nout << "request_ready, calling " << _func << "\n" << flush;
+  nout << "request_ready, calling " << (void *)_func << "\n" << flush;
   if (_func != NULL) {
     _func(this);
   }
+  nout << "done calling " << (void *)_func << "\n" << flush;
 
   // Synchronous notification for pollers.
   P3DInstanceManager *inst_mgr = P3DInstanceManager::get_global_ptr();
diff --git a/direct/src/plugin/p3dInstanceManager.cxx b/direct/src/plugin/p3dInstanceManager.cxx
index 77067b7150..42865e8319 100644
--- a/direct/src/plugin/p3dInstanceManager.cxx
+++ b/direct/src/plugin/p3dInstanceManager.cxx
@@ -23,6 +23,7 @@
 #else
 #include <fcntl.h>
 #include <sys/stat.h>
+#include <errno.h>
 #endif
 
 P3DInstanceManager *P3DInstanceManager::_global_ptr;
@@ -170,12 +171,16 @@ finish_instance(P3DInstance *inst) {
 ////////////////////////////////////////////////////////////////////
 P3DInstance *P3DInstanceManager::
 check_request() {
+  nout << "check_request\n" << flush;
   Instances::iterator ii;
   for (ii = _instances.begin(); ii != _instances.end(); ++ii) {
     P3DInstance *inst = (*ii);
+    cerr << "  checking request for " << inst << "\n" << flush;
     if (inst->has_request()) {
+      cerr << "    true\n" << flush;
       return inst;
     }
+    cerr << "    false\n" << flush;
   }
 
   return NULL;
diff --git a/direct/src/plugin/p3d_plugin_config.h.pp b/direct/src/plugin/p3d_plugin_config.h.pp
index f296ad1a23..0d36025263 100644
--- a/direct/src/plugin/p3d_plugin_config.h.pp
+++ b/direct/src/plugin/p3d_plugin_config.h.pp
@@ -20,6 +20,10 @@
    string for the default. */
 #$[]define P3D_PLUGIN_P3DPYTHON "$[subst \,\\,$[osfilename $[P3D_PLUGIN_P3DPYTHON]]]"
 
+/* Temporary: the location at which p3d_plugin.dll can be found.  Empty
+   string for the default. */
+#$[]define P3D_PLUGIN_P3D_PLUGIN "$[osfilename $[P3D_PLUGIN_P3D_PLUGIN]]"
+
 /* The string that corresponds to this particular platform. */
 #if $[not $[P3D_PLUGIN_PLATFORM]]
   #if $[WINDOWS_PLATFORM]
diff --git a/direct/src/plugin_npapi/ppInstance.cxx b/direct/src/plugin_npapi/ppInstance.cxx
index fc9909c104..6cc963deb4 100644
--- a/direct/src/plugin_npapi/ppInstance.cxx
+++ b/direct/src/plugin_npapi/ppInstance.cxx
@@ -212,13 +212,6 @@ destroy_stream(NPStream *stream, NPReason reason) {
     }
     break;
 
-  case PPDownloadRequest::RT_core_dll:
-    // This is the one case we don't start with GetUrlNotify, so we'll
-    // never get a url_notify call on this one.  So, we have to delete
-    // the PPDownloadRequest object here.
-    delete req;
-    break;
-
   default:
     break;
   }
@@ -255,17 +248,12 @@ url_notify(const char *url, NPReason reason, void *notifyData) {
       req->_notified_done = true;
     }
     break;
-
-  case PPDownloadRequest::RT_core_dll:
-    // Shouldn't be possible to get here.
-    assert(false);
-    break;
     
   default:
     break;
   }
   
-  delete req;
+  //  delete req;
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -306,14 +294,21 @@ stream_as_file(NPStream *stream, const char *fname) {
   PPDownloadRequest *req = (PPDownloadRequest *)(stream->notifyData);
   switch (req->_rtype) {
   case PPDownloadRequest::RT_core_dll:
-    // This is the core API DLL (or dylib or whatever).  Now that
-    // we've downloaded it, we can load it.
-    logfile << "got plugin\n";
-    if (!load_plugin(filename)) {
-      logfile << "Unable to launch core API.\n";
-      break;
+    {
+      // This is the core API DLL (or dylib or whatever).  Now that
+      // we've downloaded it, we can load it.
+      logfile << "got plugin " << filename << "\n" << flush;
+      string override_filename = P3D_PLUGIN_P3D_PLUGIN;
+      if (!override_filename.empty()) {
+        filename = override_filename;
+      }
+      if (!load_plugin(filename)) {
+        logfile << "Unable to launch core API.\n";
+        break;
+      }
+      logfile << "loaded core API " << filename << "\n" << flush;
+      create_instance();
     }
-    create_instance();
     break;
 
   case PPDownloadRequest::RT_instance_data:
diff --git a/direct/src/plugin_npapi/startup.cxx b/direct/src/plugin_npapi/startup.cxx
index dda0f0b997..157d4b914f 100644
--- a/direct/src/plugin_npapi/startup.cxx
+++ b/direct/src/plugin_npapi/startup.cxx
@@ -47,6 +47,7 @@ static void
 handle_request_loop() {
   assert(is_plugin_loaded());
 
+  logfile << "about to call P3D_check_request()\n" << flush;
   P3D_instance *p3d_inst = P3D_check_request(false);
   logfile << "P3D_check_request() returns " << p3d_inst << "\n" << flush;
   while (p3d_inst != (P3D_instance *)NULL) {
@@ -100,14 +101,17 @@ request_ready(P3D_instance *instance) {
   // Since we might be in a sub-thread at this point, use a timer to
   // forward this event to the main thread.
 
-  ACQUIRE_LOCK(_timer_lock);
 #ifdef _WIN32
+  ACQUIRE_LOCK(_timer_lock);
   if (_timer == 0) {
     _timer = SetTimer(NULL, 0, 0, win_timer_func);
     logfile << "_timer = " << _timer << "\n" << flush;
   }
-#endif
   RELEASE_LOCK(_timer_lock);
+#else
+  // TODO: send the message to the main thread properly.
+  handle_request_loop();
+#endif
 }