The influence of rotation and finite size of the radiation source on the orbits of dust particles around stars is analyzed. It is found that there are physical situations in which the results first derived by Robertson (Poynting-Robertson effect), corresponding to a nonrotating point-like source, cannot properly describe the dynamical behavior of the dust. The inclusion of rotation in the treatment leads to a new equations in which the tangential force depends on the rotation of the source and on the structural properties of the dust grains. For a narrow range of dust particle sizes, lower limited by the radiation pressure limit, it is shown that stable orbits exist under radiation forces.