New versions of the oik and oik-nivo-slider plugins were released to WordPress.org on 30th April 2012.
Since oik-nivo-slider is dependent upon oik I added some code so that when you visit the Administration part of the site then you’d get a message telling you if the required version of oik is not activated. Until you satisfy the pre-requisite you won’t be able to make the oik nivo slider do anything.