The plugin_load test fails on PPC64 (maybe not always, but at least in the
several tries I've made so far).  It doesn't fail on x86, x86_64, or ppc,
at least not in a similarly small number of tries.  My best theory at the
moment is that the test itself is wrong.  Reported upstream at
http://bugs.mysql.com/bug.php?id=42144

For the moment, just disable this test.

Also, disable the outfile_loaddata test, which as of 5.1.38 is giving
platform-dependent results, with the "expected" results being arguably the
wrong ones.  This is upstream at http://bugs.mysql.com/bug.php?id=46895

--- mysql-5.1.48/mysql-test/t/disabled.def.orig	2010-06-03 18:17:34.000000000 +0200
+++ mysql-5.1.48/mysql-test/t/disabled.def	2010-06-17 17:34:14.301366397 +0200
@@ -12,3 +12,6 @@
 kill                     : Bug#37780 2008-12-03 HHunger need some changes to be robust enough for pushbuild.
 query_cache_28249        : Bug#43861 2009-03-25 main.query_cache_28249 fails sporadically
 partition_innodb_plugin  : Bug#53307 2010-04-30 VasilDimov valgrind warnings
+#
+plugin_load         : gives wrong answer on PPC64
+outfile_loaddata    : gives different results on different platforms