Yay! Fixed the Next Prev buttons issue. Sorry it took so long and I appreciate that this may be irrelevant now but it may help someone out.
Find "includes/modules/your_template/additional_images.php
Replace the following code.....
* if (ZEN_LIGHTBOX_STATUS == 'true' || FUAL_SLIMBOX == 'true') {
if (ZEN_LIGHTBOX_GALLERY_MODE == 'true') {
$rel = 'lightbox-g';
} else {
$rel = 'lightbox';
}
$script_link = '<script language="javascript" type="text/javascript"><!--' . "\n" . 'document.write(\'' . ($flag_display_large ? '<a href="' . zen_lightbox($products_image_large, addslashes($products_name), LARGE_IMAGE_WIDTH, LARGE_IMAGE_HEIGHT) . '" rel="' . $rel . '" title="' . addslashes($products_name) . '">' . $thumb_slashes . '<br />' . TEXT_CLICK_TO_ENLARGE . '</a>' : $thumb_slashes) . '\');' . "\n" . '//--></script>';
} else {
$script_link = '<script language="javascript" type="text/javascript"><!--' . "\n" . 'document.write(\'' . ($flag_display_large ? '<a href="javascript:popupWindow(\\\'' . str_replace($products_image_large, urlencode(addslashes($products_image_large)), $large_link) . '\\\')">' . $thumb_slashes . '<br />' . TEXT_CLICK_TO_ENLARGE . '</a>' : $thumb_slashes) . '\');' . "\n" . '//--></script>';
}*
with
*
if (ZEN_LIGHTBOX_STATUS == 'true' || FUAL_SLIMBOX == 'true') {
$script_link = '<script language="javascript" type="text/javascript"><!--' . "\n" . 'document.write(\'' . ($flag_display_large ? '<a href="' . zen_lightbox($products_image_large, addslashes($products_name), LARGE_IMAGE_WIDTH, LARGE_IMAGE_HEIGHT) . '" rel="lightbox[gallery]" title="' . addslashes($products_name) . '">' . $thumb_slashes . '<br />' . TEXT_CLICK_TO_ENLARGE . '</a>' : $thumb_slashes) . '\');' . "\n" . '//--></script>';
} else {
$script_link = '<script language="javascript" type="text/javascript"><!--' . "\n" . 'document.write(\'' . ($flag_display_large ? '<a href="javascript:popupWindow(\\\'' . $large_link . '\\\')">' . $thumb_slashes . '<br />' . TEXT_CLICK_TO_ENLARGE . '</a>' : $thumb_slashes) . '\');' . "\n" . '//--></script>';
}*
Hope this helps someone out.