Despite upgrading to MongoDB 1.8.2, we're still seeing mongos attempt setShardVersion on slave MongDB instances (like those described in SERVER-2961).

Here's what we see in the mongos logs:
Sun Jun 19 17:38:33 [conn627] ns: users.user_badges ClusteredCursor::query ShardConnection had to change attempt: 0
Sun Jun 19 17:38:33 [conn627] setShardVersion failed host[mongo-c01r03s03:27018]

{ errmsg: "not master", ok: 0.0 }

Sun Jun 19 17:38:33 [conn627] Assertion: 10429:setShardVersion failed host[mongo-c01r03s03:27018]

{ errmsg: "not master", ok: 0.0 }

0x5204fa 0x6a15ed 0x6a1152
/usr/bin/mongos(_ZN5mongo11msgassertedEiPKc+0x12a) [0x5204fa]
/usr/bin/mongos() [0x6a15ed]
/usr/bin/mongos() [0x6a1152]

Here's the output of --version for that mongos instance:
Sun Jun 19 17:45:09 mongos db version v1.8.2, pdfile version 4.5 starting (--help for usage)
Sun Jun 19 17:45:09 git version: 433bbaa14aaba6860da15bd4de8edf600f56501b
Sun Jun 19 17:45:09 build sys info: Linux bs-linux64.10gen.cc 2.6.21.7-2.ec2.v1.2.fc8xen #1 SMP Fri Nov 20 17:48:28 EST 2009 x86_64 BOOST_LIB_VERSION=1_41

All mongod instances in the cluster (including config server instances) are running 1.8.2.