Active Record is producing wrong SQL. Please help

[eluser]FutureKing[/eluser]
Hi,
I am trying to make a RSS2.0 feed reader with code igniter. This app will to the following task:
1. Downloading RSS2.0 feed from URL
2. Insert everything in MySQL Database.

for second step I am using Active Record Insert But I am getting following error:

Code:

A Database Error Occurred
Error Number: 1064

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'News, http://news.google.com/, Google News, Fri, 08 May 2009 07:48:16 GMT, 'http' at line 1

INSERT INTO `feed_urls` (`f_title`, `f_link`, `f_desc`, `f_date`, `f_url`) VALUES (Google News, http://news.google.com/, Google News, Fri, 08 May 2009 07:48:16 GMT, 'http://news.google.com/?output=rss')

I am using SimpleXmlElement for Downloading feeds.(see tutorial: http://nettuts.com/javascript-ajax/how-t...creencast/)
Why there is no inverted comma on my SQL query?