Trying to add an image to my main menu

Hi there,

I'm trying to add an image to my main menu and have found an article on gavick regaring this very subject (http://www.gavick.com/magazine/how-to-add-icons-to-joomla-menu.html) so I assume it can be done, however, I've tried to add in a Facebook and Twitter icon (.png file) but it only shows the text link not the icon.
I'm using joomla 2.5.6 and my URL is http://www.naturezone.co.za
Thanks

Hi,
Can you send me Private Message with access to your joomla back-end ?

OK PM sent (I think, I've never used the message system before) its sitting in my outbox so I have no idea if you received it.
Thanks

I' ve got your message. I see that your template version is 2.10, please update it to the latestes version and let me know if issue still remain.

I' ve got your message. I see that your template version is 2.10, please update it to the latestes version and let me know if issue still remain.

Thanks Konrad, I'll try that and let you know. I just need to back up my stylesheets first.