Newbie need help!

[eluser]LAMPguru[/eluser]
Hi all,

I've been using codeIgniter for about 6 hours, and I like it so far.
I have one small problem, when I click on a link to either go to a new page or a simple submit button, I would get this:
ex: http://domain.com/index.php/article/index.php/article/5,


here's the scenario:
1) I'm on this page
http://domain.com/index.php/article/

2) I click on article 5

3) instead of going to http://domain.com/index.php/article/5, I would get http://domain.com/index.php/article/index.php/article/5

I'm running codeigniter on a apache server with load mod_rewrite enable and I also added the .htaccess file in the root folder with the basic rewrite directions.
Here's the rewrite file info:

##RewriteEngine on
##RewriteCond $1 !^(index\.php|user_guide|robots\.txt)
##RewriteRule ^(.*)$ /index.php?/$1 [L]


Thanks for you help,