1.2.1 Upgrade Problem

I upgraded to 1.2.1 and now I’m getting this error message on my site at http://www.thehackworths.com :

Warning: fopen(/home/jennyp/public_html/wordpress/wp-content/links-update-cache.xml): failed to open stream: Permission denied in /home/jennyp/public_html/wordpress/wp-includes/links-update-xml.php on line 79
Warning: fwrite(): supplied argument is not a valid stream resource in /home/jennyp/public_html/wordpress/wp-includes/links-update-xml.php on line 80
Warning: fclose(): supplied argument is not a valid stream resource in /home/jennyp/public_html/wordpress/wp-includes/links-update-xml.php on line 81

Can someone tell me how to fix this please?