intermittent FD regression check failure

The sort of failure shown below has happened a few times recently. See 
recent failures on crake, mastodon and casteroides at 
<http://www.pgbuildfarm.org/cgi-bin/show_failures.pl>. It seems harmless 
enough. Do we need an alternative regression results file, or is there 
some way to prevent this?

cheers

andrew
   *** /home/bf/bfr/root/HEAD/pgsql.4238/../pgsql/src/test/regress/expected/foreign_data.out    Fri Apr  1 11:37:02
2011  --- /home/bf/bfr/root/HEAD/pgsql.4238/src/test/regress/results/foreign_data.out    Mon Apr 25 09:41:48 2011
***************  *** 1088,1098 ****      DROP USER MAPPING FOR regress_test_role SERVER s6;      DROP FOREIGN DATA
WRAPPERfoo CASCADE;      NOTICE:  drop cascades to 5 other objects   ! DETAIL:  drop cascades to server s4      drop
cascadesto user mapping for foreign_data_user      drop cascades to server s6   - drop cascades to server s9   - drop
cascadesto user mapping for unprivileged_role      DROP SERVER s8 CASCADE;      NOTICE:  drop cascades to 2 other
objects     DETAIL:  drop cascades to user mapping for foreign_data_user   --- 1088,1098 ----      DROP USER MAPPING
FORregress_test_role SERVER s6;      DROP FOREIGN DATA WRAPPER foo CASCADE;      NOTICE:  drop cascades to 5 other
objects  ! DETAIL:  drop cascades to server s9   ! drop cascades to user mapping for unprivileged_role   ! drop
cascadesto server s4      drop cascades to user mapping for foreign_data_user      drop cascades to server s6      DROP
SERVERs8 CASCADE;      NOTICE:  drop cascades to 2 other objects      DETAIL:  drop cascades to user mapping for
foreign_data_user