you could try the load method in jQuery:
code assumes you are using css to display:none the ul in the slider, then once the jquery is ready it will show the ul (and the images I am assuming) then once the #mini_mac_slider container and all of its sub-elements has finished loading (based on .load()) then it will initiate the slider plugin.
Hope that helps. You can also start the slider out by showing a default image, wait for the load, hide the default then do the .show() on the ul. I guess there are a lot of ways of doing it.