I have a record in my database but it doesn't seem to be indexed correctly.
I have a compound index
{
"v" : 1,
"key" :

{ "device" : 1, "time" : -1 }

,
"ns" : "loco.history",
"name" : "device_1_time_-1"
},

and this is used to run the query.

locobase:SECONDARY> db.history.find({device:357207050859404,"time":{"$gt":start,"$lt":end}}).explain()
{
"cursor" : "BtreeCursor device_1_time_-1",
"isMultiKey" : false,
"n" : 19,
"nscannedObjects" : 19,
"nscanned" : 19,
"nscannedObjectsAllPlans" : 19,
"nscannedAllPlans" : 19,
"scanAndOrder" : false,
"indexOnly" : false,
"nYields" : 0,
"nChunkSkips" : 0,
"millis" : 0,
"indexBounds" :

{ "device" : [ [ 357207050859404, 357207050859404 ] ], "time" : [ [ ISODate("2015-04-01T00:00:00Z"), ISODate("2010-04-01T00:00:00Z") ] ] }

,
"server" : "uk4.loco-pos.net:27017"
}

note: there are 19 items found

but if I give a hint to not use the time field in the index I get

locobase:SECONDARY> db.history.find({device:357207050859404,"time":{"$gt":start,"$lt":end}}).hint(

{device:1}

).explain()
{
"cursor" : "BtreeCursor device_1",
"isMultiKey" : false,
"n" : 19,
"nscannedObjects" : 20,
"nscanned" : 20,
"nscannedObjectsAllPlans" : 20,
"nscannedAllPlans" : 20,
"scanAndOrder" : false,
"indexOnly" : false,
"nYields" : 0,
"nChunkSkips" : 0,
"millis" : 0,
"indexBounds" :

{ "device" : [ [ 357207050859404, 357207050859404 ] ] }

,
"server" : "uk4.loco-pos.net:27017"
}

now there are 20 items.

The missing item has
locobase:SECONDARY> db.history.findOne({_id:ObjectId("533a8bf3d6e909b3c29e6e38")}).time
ISODate("2014-04-01T09:50:43.487Z")

as far as I know, There are no other records with this problem and everything else seems normal.
I realise 2.2.2 is quite old but this may still be relevant.