--- mapows.c   (revision new)
+++ mapows.c   (working copy)

@@ -1180,7 +1180,11 @@
 
   /* always project to lat long */
   if (srcproj->numargs > 0 && !pj_is_latlong(srcproj->proj)) {
-      msProjectRect(srcproj, NULL, &ext);
+      projectionObj wgs84;
+      msInitProjection(&wgs84);
+      msLoadProjectionString(&wgs84, "+proj=longlat +datum=WGS84");
+      msProjectRect(srcproj, &wgs84, &ext);
+      msFreeProjection(&wgs84);
   }