Index: libmng_zlib.c
===================================================================
--- libmng_zlib.c.orig
+++ libmng_zlib.c
@@ -163,6 +163,9 @@ mng_retcode mngzlib_inflateinit (mng_dat
 #ifdef MNG_SUPPORT_TRACE
   MNG_TRACE (pData, MNG_FN_ZLIB_INFLATEINIT, MNG_LC_START);
 #endif
+
+  if (pData->bInflating)               /* free the old zlib structures */
+     inflateEnd(&pData->sZlib);
                                        /* initialize zlib structures and such */
   iZrslt = inflateInit (&pData->sZlib);