Problem:
Can't seen to combine $within with additional predicate

Reproduce:

> db.testcol.find()
{ "_id" : "1", "title" : "Doc1", "loc" :

{ "lat" : 0, "lng" : 1 }

, "occurences" : [

{ "instanceId" : 1, "startDate" : ISODate("2001-01-23T03:00:00Z") }

,

{ "instanceId" : 2, "startDate" : ISODate("2011-01-30T03:00:00Z") }

] }
{ "_id" : "2", "title" : "Doc2", "loc" :

{ "lat" : 0, "lng" : 1 }

, "occurences" : [

{ "instanceId" : 1, "startDate" : ISODate("2011-01-24T03:00:00Z") }

,

{ "instanceId" : 2, "startDate" : ISODate("2011-01-25T03:00:00Z") }

] }

This works

> db.testcol.find({ "loc": { "$within":
...

{ "$box": [ [ 0, 0 ], [ 1, 1 ] ] }

}
... })
{ "_id" : "1", "title" : "Doc1", "loc" :

{ "lat" : 0, "lng" : 1 }

, "occurences" : [

{ "instanceId" : 1, "startDate" : ISODate("2001-01-23T03:00:00Z") }

,

{ "instanceId" : 2, "startDate" : ISODate("2011-01-30T03:00:00Z") }

] }
{ "_id" : "2", "title" : "Doc2", "loc" :

{ "lat" : 0, "lng" : 1 }

, "occurences" : [

{ "instanceId" : 1, "startDate" : ISODate("2011-01-24T03:00:00Z") }

,

{ "instanceId" : 2, "startDate" : ISODate("2011-01-25T03:00:00Z") }

] }

However, restricting by occurences.startDate returns no documents

> db.testcol.find({ "loc": { "$within":
...

{ "$box": [ [ 0, 0 ], [ 1, 1 ] ] }

},
... "occurences.startDate":
... { "$gte": new Date(2011,0,23)}})