--- gimp-2.6.6/plug-ins/metadata/xmp-parse.c	2008-09-25 20:00:50.000000000 +0200
+++ plug-ins/metadata/xmp-parse.c	2009-07-10 12:05:22.000000000 +0200
@@ -924,6 +924,11 @@
       break;
 
     case STATE_INSIDE_ALT:
+      if (context->property && context->prop_cur_value < 0)
+        {
+          g_free (context->property);
+          context->property = NULL;
+        }
     case STATE_INSIDE_BAG:
     case STATE_INSIDE_SEQ:
       context->state = STATE_INSIDE_PROPERTY;
