The id attribute must be unique within a document. This is a problem on the Dashboard with jquery 1.4.x (and its optimized selector code).
Examples (non-exhaustive list):
I dont think we should change this now as this wouldn't change anything, plus in the feature I think it would make more sense to rewrite the datatable JS code to make it more simple (only read JSON from server and have the presentation fully in JS, rather than hacking the DOM as it is now).
vote for wontfix