So far, so good. the slideshow is working well, and quickly. It took me a while to figure out how to center it using css.
This link was helpful,
But perhaps he's talking about an earlier version.
The key seems to be, the css you're working on is in wp-content/plugins/portfolio slideshow/styles.css
And you need to change the css for the appropriate divs to a width, and auto margins left and right, as per the link above.
Thanks for a great plugin!