getBulkRequest not working with addCustomReport

Am I going crazy, or is anyone else experiencing this?

I am trying to programmatically manage custom reports across multiple sites. But when I try to bulk them together I get the error Please specify a value for 'metricIds'. on each request.

  1. I am encoding the urls, and have confirmed my bulk request utility works fine for other requests.
  2. The individual requests also work fine if I just fire them separately instead.

Just me?