After upgrading I can't search more than one word... Take a look...

www.aretimes.com/component/option,com_ku...file+does+not+exist/

I know for a fact that those words are in posts.

You are using an old version of Kunena (K 1.0.11) that was provided as an end-of-life release for Joomla 1.0.x. This version of Kunena is not supported - neither is Joomla 1.0.x. You are also using a Kunena template (default), that is strongly discouraged.

You are advised to upgrade to Joomla 1.5.15 and Kunena 1.5.9. The search problem you have referred to was a known problem - and never completely fixed - in K 1.0.X caused by using an unsupported Kunena template (see Search not working).