If you visit this js fiddle http://jsfiddle.net/aGcVd/4/ then click the "Last" link you will be prompted with a confirm dialog. Clicking cancel will prevent the fnDraw function from being called. Unfortunately, the link handler will have already updated oSettings._iDisplayStart. As a result any subsequent clicks on the "Last" link will not call fnDraw.
I have created a fix for this bug on my local repo that can be seen here. bmac@ea3f9d5
Unfortunately, this fix makes use of events internally so I am not convinced it is the best solution.