When running a mongodump on all members of a replica set, I see this error on the mongod server (all of them).
I run mongodump against the primary and both secondaries and I see the same error on all.

I ran a db.repairDatabase() and still getting the same.

This is new since 1.7.5 upgrade from 1.6.5

Fri Feb 11 14:39:11 [initandlisten] connection accepted from 10.12.57.162:37054 #56322
Fri Feb 11 14:39:11 [conn51176] warning: no id index on $snapshot query, ns:094410ee3c5d4757be2885586235f19d.LEADEBOARD_sp_dev_chkall1_d_1294898400000.$_id
Fri Feb 11 14:39:11 [conn51176] Assertion: 10334:Invalid BSONObj size: -1 (0xFFFFFFFF) first element: EOO
0x560819 0x4ed88e 0x780128 0x65a67b 0x788566 0x791091 0x794815 0x796d44 0x7978e7 0x643c7d 0x74dc0c 0x75399d 0x89a15e 0x8ad550 0x7f6b3fb839ca 0x7f6b3f13270d
/usr/bin/mongod(_ZN5mongo11msgassertedEiPKc+0x129) [0x560819]
/usr/bin/mongod(_ZNK5mongo7BSONObj14_assertInvalidEv+0x46e) [0x4ed88e]
/usr/bin/mongod(_ZN5mongo11BasicCursor7currentEv+0x68) [0x780128]
/usr/bin/mongod(_ZN5mongo11UserQueryOp4nextEv+0x7cb) [0x65a67b]
/usr/bin/mongod(_ZN5mongo12QueryPlanSet6Runner6nextOpERNS_7QueryOpE+0x56) [0x788566]
/usr/bin/mongod(_ZN5mongo12QueryPlanSet6Runner3runEv+0x861) [0x791091]
/usr/bin/mongod(_ZN5mongo12QueryPlanSet5runOpERNS_7QueryOpE+0x255) [0x794815]
/usr/bin/mongod(_ZN5mongo16MultiPlanScanner9runOpOnceERNS_7QueryOpE+0x64) [0x796d44]
/usr/bin/mongod(_ZN5mongo16MultiPlanScanner5runOpERNS_7QueryOpE+0x17) [0x7978e7]
/usr/bin/mongod(ZN5mongo8runQueryERNS_7MessageERNS_12QueryMessageERNS_5CurOpES1+0xdfd) [0x643c7d]
/usr/bin/mongod() [0x74dc0c]
/usr/bin/mongod(_ZN5mongo16assembleResponseERNS_7MessageERNS_10DbResponseERKNS_8SockAddrE+0x5ad) [0x75399d]
/usr/bin/mongod(_ZN5mongo10connThreadEPNS_13MessagingPortE+0x21e) [0x89a15e]
/usr/bin/mongod(thread_proxy+0x80) [0x8ad550]
/lib/libpthread.so.0(+0x69ca) [0x7f6b3fb839ca]
/lib/libc.so.6(clone+0x6d) [0x7f6b3f13270d]
Fri Feb 11 14:39:11 [conn51176] assertion 10334 Invalid BSONObj size: -1 (0xFFFFFFFF) first element: EOO ns:094410ee3c5d4757be2885586235f19d.LEADEBOARD_sp_dev_chkall1_d_1294898400000.$id query:{ query: {}, $snapshot: true }
Fri Feb 11 14:39:11 [conn51176] end connection 10.12.57.162:37054