[Plugin: Tumblr Widget] Error: Couldn't resolve host ..

Hi all,
This plugin worked well while my site was in development, on my Bluehost development server. Then when I moved my site to production, on the client’s account at Small Orange, I got this error :

Error: Couldn’t resolve host ‘mytumblr.tumblr.com’

I’ve tried deleting+ reinstalling the widget, double checked the tumblr url, tried the tumblr url with an added ‘http://’ , all without luck. I suspect this is something related to server configuration, since it works fine on my other server.

My php version is 5.3.13, and cURL and SimpleXML are enabled.

I’m fairly confident this isnt a problem with tumbr’s server, since the widget works fine on my testbed, which is an exact mirror.

Can anyone point me in the right direction?

http://ww.wp.xz.cn/extend/plugins/tumblr-widget-for-wordpress/