Breakpoints won't work on dynamically loaded libraries

Hi,

I have js libraries loaded dynamically :

require(["dojo/ready", "js/lgonlineBuildUI"], function (ready) {
     ready(function () {
     ...

When I put breakpoints in one of these libraries they are ignored (they are not in Firebug though).
However breakpoints in embeded JavaScript or loaded from the HTML vis <script> work perfectly.

Is there a solution to it ?

Thanks