I am trying to make a test post to my tumblr blog with a php script (that will eventually be ran as a cron job)

I have been browsing google and read many answers on here and the closest I found is explained in this post:

Tumblr OAuth using PHP's OAuth class

I am using the code in his tutorial here:

http://vigrond.com/blog/2012/02/04/oauth-extension-php-and-the-tumblr-api/

Pretty much as is, replacing the blogurl with mine and of course the consumer and secret key.

When I run the .php script via my browser however, nothing happens.

Any ideas?

EDIT: The only error I found in cPanel's error log is this:

[Wed Oct 31 00:29:25 2012] [error] [client xx.xx.xx.xx ] PHP Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /path on line 14

But I fixed this and the error does not appear anymore.