Podcasting Activation Error

When trying to activate the Podcasting pluggin I received the following error:

Fatal error: Call to undefined function: add_shortcode() in /hermes/bosweb/web204/b2041/ipw.reshma80/public_html/blog/wp-content/plugins/podcasting/podcasting.php on line 48

Downloaded and reinstalled several times. Stumped for the nest thing to try. Any ideas would be welcome.

Thanks,

Gene