Contact API country fields not functioning properly anymore

I have a bit of custom code on one site that pulls contacts based on 'Primary Address country' as follows (example):

$contactcount=civicrm_api("Contact","getcount", array ('version' =>'3', 'contact_type' =>'Organization', 'country' =>'United States');

When I try this on the API Explorer on the demo site, I get this error:

"error_message":"A fatal error was triggered: United States is not of the type Positive"

It seems to have stopped working with an upgrade from 4.6.7 to 4.6.9. Did something change in the API call?

Update:

I was trying to rough in some temporary code to make this functional by using the Country ID instead of the Country Name, and there seems to be a problem there, too. The country ID field in the API seems to be essentially ignored.

$contactcount=civicrm_api("Contact","getcount", array ('version' =>'3', 'contact_type' =>'Organization', 'country_id' => 1228);

I verified this on the demo site, too.