Without knowing Cygwin, this seems to make more sense to me?!

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@7030 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

src/Fl_Preferences.cxx

@@ -1840,7 +1840,7 @@ int Fl_Plugin_Manager::load(const char *filename)
 {
   // the functions below will autmaticaly load plugins that are defined:
   // Fl_My_Plugin plugin();
-#ifdef WIN32
+#if defined(WIN32) && !defined(__CYGWIN__)
   HMODULE dl = LoadLibrary(filename);
 #else
   void * dl = dlopen(filename, RTLD_LAZY);