To centre the images in the slider, you need to alter the css of the template.
For example, to modify the default template:
Open the style.css file in plugins/cyclone-slider-2/templates/default
Find the css rule .cycloneslider-template-default .cycloneslider-slide img
In the current version of the slider this is line 18 of style.css
Change
margin:0;
to
margin:0 auto;
The images are now centred.