Demand version 2.5.1 since 2.5 has a bug with codecs.open context managers.
diff --git a/Python/import.c b/Python/import.c
index 678a30b..dc97940 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -1395,6 +1395,7 @@
 			filemode = fdp->mode;
 			if (filemode[0] == 'U')
 				filemode = "r" PY_STDIOTEXTMODE;
+			errno = 0;
 			fp = fopen(buf, filemode);
 			if (fp != NULL) {
 				if (case_ok(buf, len, namelen, name))
@@ -1404,6 +1405,15 @@
 					fp = NULL;
 				}
 			}
+			/* issue a warning if the file is there */
+			/*if (errno != ENOENT) {
+				char warnstr[MAXPATHLEN+80];
+				sprintf(warnstr, "Not importing '%.*s': ");
+				
+				if (PyErr_Warn(PyExc_ImportWarning,
+					       warnstr)) {
+
+			}*/
 #if defined(PYOS_OS2)
 			/* restore the saved snapshot */
 			strcpy(buf, saved_buf);