jstests/sharding/shard_insert_getlasterror_w2.js is failing on multiple platforms. Indications are that this may be a race condition; the failures do not seem to happen on fast machines. On Windows, they have been seen so far only in debug builds, though on Linux they have been seen in release builds.

Some failures:
http://buildbot.mongodb.org/builders/Nightly%20Linux%2032-bit/builds/1228/steps/test_11/logs/stdio
http://buildlogs.mongodb.org/Nightly%20Linux%2032-bit/builds/1228/test/sharding/shard_insert_getlasterror_w2.js

http://buildbot.mongodb.org/builders/Nightly%20Linux%20RHEL%2032-bit/builds/398/steps/test_11/logs/stdio
http://buildlogs.mongodb.org/Nightly%20Linux%20RHEL%2032-bit/builds/398/test/sharding/shard_insert_getlasterror_w2.js

http://buildbot.mongodb.org/builders/Nightly%20Linux%2032-bit/builds/1226/steps/test_11/logs/stdio
http://buildlogs.mongodb.org/Nightly%20Linux%2032-bit/builds/1226/test/sharding/shard_insert_getlasterror_w2.js

http://buildbot.mongodb.org/builders/Windows%2064-bit%202008%2B%20DEBUG/builds/637/steps/test_11/logs/stdio
http://buildlogs.mongodb.org/Windows%2064-bit%202008%2B%20DEBUG/builds/637/test/sharding/shard_insert_getlasterror_w2.js

http://buildbot.mongodb.org/builders/Windows%2064-bit%20DEBUG/builds/596/steps/test_11/logs/stdio
http://buildlogs.mongodb.org/Windows%2064-bit%20DEBUG/builds/596/test/sharding/shard_insert_getlasterror_w2.js