[Plugin: TBTestimonials] Shortcode conflict ? and 404 preview error

Hi, great little plugin this is, however I can only get it to work in a plain vanilla wordpress installation thats uses twenty-eleven theme.

On my other wordpress installation that uses a downloaded theme from elsewhere, the shortcode [testimonial] is perhaps conflicting with a shortcode within the theme, so, how can I go about changing the shortcode name, to perhaps [tb_testimonial] instead ? Ive tried editing the following line within tb-testimonials.php, but it has no effect.

add_shortcode( ‘testimonial’, array( &$this, ‘shortcode’ ) );

When I create a new page and add the shortcode to it within the WYSIWYG editor, and preview the page, it merely shows the shortcode code so its not hooking up.

Also, within the testimonials admin area, when I want to preview a testimonial, Im getting a 404 error. I have permalinks switched on and am using the Post name setting (/%postname%)

Any info much appreciated

https://www.ads-software.com/extend/plugins/tb-testimonials/