I've got #slide-next and #slide-previous sitting to the sides of my slides. All fine in IE7-9 and Firefox. Chrome, oddly, puts them somewhere else.
Are you sure you've refreshed your browser/cleared you cache? They look fine in Chrome to me.
Whoa. That was it. D'oh to me.
When viewing web designs, it is best to have your browser set to check for a new version of the page with every visit. Changes may not be reflected if your browser is using the default settings for page caching.