Try updating to the development version of Meta Slider, I've updated it so slideshows shouldn't be returned in search results. To install the development version:
- Go to http://wordpress.org/plugins/ml-slider/developers/
- Download the 'Development version' (under 'Other Versions')
- Log into WordPress
- Go to Plugins > Installed Plugins
- Deactivate and Delete Meta Slider (you will not lose your slides)
- Go to Plugins > Add New > Upload
- Select the development version zip file from your computer