This is a known bug in Mozilla.
There is a bug in the jsd (the debugging module of the Mozilla engine) dealing with code defined by an eval statement. If the code run by the eval is brought up in the debugger, it is reported as the line of code which executed the eval itself, plus the line offset within the eval. Since Dojo uses xhr + eval to load all code outside of the bootstrap, this is what you will typically see throughout your callstack when attempting to debug Dojo code in Mozilla.
