ISODate does not round trip through export and import of csv

$ ./mongo

MongoDB shell version: 2.5.1-pre-

connecting to: test

> db.test.insert({"d":ISODate()})

> db.test.find()

{ "_id" : ObjectId("51db91d2d8e6bfa42833443d"), "d" : ISODate("2013-07-09T04:30:10.144Z") }

> exit

bye

$ ./mongoexport --csv --fields d -d test -c test -o test.csv

connected to: 127.0.0.1

exported 1 records

$ ./mongoimport --type csv -c test -d test --headerline test.csv

connected to: 127.0.0.1

Tue Jul  9 00:30:37.219 imported 1 objects

$ ./mongo

MongoDB shell version: 2.5.1-pre-

connecting to: test

> db.test.find()

{ "_id" : ObjectId("51db91d2d8e6bfa42833443d"), "d" : ISODate("2013-07-09T04:30:10.144Z") }

{ "_id" : ObjectId("51db91ed140f5f1801700482"), "d" : "2013-07-09T04:30:10Z" }

>