--- IO-AIO/AIO.xs	2010/05/09 20:49:52	1.167
+++ IO-AIO/AIO.xs	2010/08/04 14:02:58	1.168
@@ -622,8 +622,11 @@
   mg->mg_obj = 0; /* just in case */
 
   SvREADONLY_off (sv);
+
+  if (SvPVX (sv) != mg->mg_ptr)
+    croak ("ERROR: IO::AIO::mmap-mapped scalar changed location, detected");
+
   SvCUR_set (sv, 0);
-  SvLEN_set (sv, 0);
   SvPVX (sv) = 0;
   SvOK_off (sv);
 
@@ -1388,14 +1391,20 @@
 	if (addr == (void *)-1)
 	  XSRETURN_NO;
 
+        sv_force_normal (scalar);
+
         /* we store the length in mg_obj, as namlen is I32 :/ */
         sv_magicext (scalar, 0, MMAP_MAGIC, &mmap_vtbl, (char *)addr, 0)
           ->mg_obj = (SV *)length;
 
 	SvUPGRADE (scalar, SVt_PV); /* nop... */
+
 	if (!(prot & PROT_WRITE))
 	  SvREADONLY_on (scalar);
 
+        if (SvLEN (scalar))
+          Safefree (SvPVX (scalar));
+
 	SvPVX (scalar) = (char *)addr;
 	SvCUR_set (scalar, length);
 	SvLEN_set (scalar, 0);