From time to time, index_intersect_innodb fails with a diff in EXPLAIN output like this.

— c:/buildbot/win32-debug/build/mysql-test/r/index_intersect_innodb.result 2011-05-29 07:42:17.476000000 +0000
+++ c:\buildbot\win32-debug\build\mysql-test\r\index_intersect_innodb.reject 2011-05-29 08:02:39.034768300 +0000
@@ -372,7 +372,7 @@
SELECT * FROM City
WHERE Name BETWEEN 'G' AND 'K' AND Population > 500000 AND Country LIKE 'C%';
id select_type table type possible_keys key key_len ref rows Extra
-1 SIMPLE City index_merge Population,Country,Name Population,Name,Country 4,35,3 NULL # Using sort_intersect(Population,Name,Country); Using where
+1 SIMPLE City index_merge Population,Country,Name Population,Country,Name 4,3,35 NULL # Using sort_intersect(Population,Country,Name); Using where
SELECT * FROM City USE INDEX ()
WHERE Name BETWEEN 'M' AND 'N' AND Population > 1000000 AND Country LIKE 'C%';
ID Name Country Population

Note the changed order of fields (Population,Name,Country) vs (Population,Country,Name)

Example of failure: http://buildbot.askmonty.org/buildbot/builders/win32-debug/builds/126/steps/test/logs/stdio