Bug #56655 for MongoDB: Wrong syntax used in upsert example

The upsert example $pageviews->update({"url" => "www.example.com"}, {"url" => "www.example.com", '$inc' => {"views" => 1}}, {'upsert' => 1}); mentioned on http://search.cpan.org/~kristina/MongoDB/lib/MongoDB/Tutorial.pod does not work for me. The error mongod reports is: Fri Apr 16 15:46:04 update tutorial.pageview query: { url: "www.example.com" } exception userassert:Invalid modifier specifiedurl 0ms This appears to be working fine instead: $pageviews->update({"url" => "www.example.com"}, {'$inc' => {"views" => 1}}, {'upsert' => 1}); No errors are reported, and records are inserted or updated as expected. This syntax is also similar to instructions provided on http://www.mongodb.org/display/DOCS/Updating#Updating-UpsertswithModifiers - example: db.people.update( { name:"Joe" }, { $inc: { x:1, y:1 } }, true ); I'm just now starting to learn about MongoDB, so I'm not certain if I have found a real bug or if I'm misunderstanding the Tutorial.