Warning: Illegal string offset 'cols' in

Every time I load the page that contains SimpleGallery, I get this error message (displayed on the page) –

Warning: Illegal string offset ‘cols’ in ..\plugins\youtube-simplegallery\youtube_simplegallery.php on line 388

The section of code where line 388 is present is as follows;

386: $youtubeoptions = get_option(‘youtube_gallery_option’);
387: $cols = $youtubeoptions[‘cols’];
388: if($atts[‘cols’]) $cols = $atts[‘cols’];

I am on WordPress 3.4.2, latet versions of MySQL, Php and SimpleGallery. My theme is TwentyTen. I am using ThickBox. The YouTube icons (pictures) and text are displaying fine, as is the text (titles), and the videos play in ThickBox when I click an icon. EVERYTHING looks and works perfectly. I just don’t know what to do to get rid of the error message that’s displayed on the page.

If anyone has any ideas, a little help would be greatly appreciated.

Thanks in advance for any responses.

http://wordpress.org/extend/plugins/youtube-simplegallery/