--- dovecot-1.0.10/src/plugins/zlib/zlib-plugin.c.orig	2008-01-17 19:02:13.175883000 +0000
+++ dovecot-1.0.10/src/plugins/zlib/zlib-plugin.c	2008-01-17 19:04:32.747173000 +0000
@@ -142,7 +142,7 @@
 	if (zlib_input != NULL)
 		i_stream_unref(&zlib_input);
 
-	if (strcmp(storage->name, "maildir") == 0) 
+	if (box != NULL && strcmp(storage->name, "maildir") == 0) 
 		zlib_maildir_open_init(box);
 	return box;
 }