Colorbox Jqueryプラグインで、スライダーやなんかと干渉するときにはFAQにもあるとおり、

http://www.jacklmoore.com/colorbox/faq/#faq-focus

Try setting returnFocus to false. Colorbox returns focus to the element it was launched from upon closing. This is intended to provide better accessibility to users who use their keyboard to navigate through the document's links, but it can cause problems with some JS effects. The problem isn't Colorbox specific and can be reproduced without Colorbox by pressing the TAB key to cycle through the available links.

returnFocusをfalseに設定してみる。

returnFocus:false

今回はスライダーとの組み合わせでcolorbox終了時にスライダーが勝手に動くことがあった。