add
$(".various21").fancybox();
to the onsuccess function. the ajax code is replacing the dom elements that fancybox setup.
note: you will have memory leaks with your code, as fancybox keeps references to dom objects, and while its events are unbound, these references are not. you might want to modify the fancybox to have a destroy or dispose method, that you can call to release the dom objects.
i have written fancybox code into partial view, which was causing loosing reference, i pull out the code from partial view and put into the normal view and removed all script also from the partial view. and it is working fine.