Thanks for sending me the info so quickly :)
Can you try downloading the most recent update of the theme from Themeforest and re-installing the theme in the same way you first installed it. There was an update in version 1.2 to bring it up to compatibility with wordpress version 3.4 which may fix your issue.
If that does not, next try disabling all active plugins, installing then running the regenerate thumbnails plugin I linked above and then finally removing the image from the slideshow on that page and then re-adding it in.
Its quite a few steps but its better to get everything running smoothly now before you add more images and content in the slider :)
Regards,
Devin