Wordpress MultiSite Sliders fix

I have an ongoing issue with a wordpress multisite install, I am unable to get sliders to work on all sites. A few sliders work on 2 mapped subdomains but not on others or my main site. Conversations with wp support suggest that it is a timthumb or file path issue. a file in each theme may need changed [login to view URL] I believe this is a straight forward fix for a seasoned coder but unfortunately, my knowledge in PHP doesn't stretch this far, so I turn to you... I would like this issue fixed in the active themes and a 'how-to' compiled for free distribution in the wordpress community, all credit to the writer.