Using single step is often quite handy, but if you have an underlying framework that supplies helper functions, stepping into these files can be annoying.
It would be useful to add an option with which you can specify that either xdebug will not step into files located within a certain directory (which I guess would be the most useful way of dealing with the issue) or at least not to step into magic methods (get, set, ...) which are often used to emulate properties and do nothing but assigning a value to an internal array.