Comment on `Solution of the Dirac equation for the Woods-Saxon potential   with spin and pseudospin symmetry' [J. Y. Guo and Z-Q. Sheng, Phys. Lett. A   338 (2005) 90]
  Out of the four bound-state solutions presented in loc. cit., only one (viz., the spin-symmetric one, in the low-mass regime) is shown compatible with the physical boundary conditions. We clarify the problem, correct the method and offer another, "missing" (viz., pseudospin-symmetric) new solution with certain counterintuitive "repulsion-generated" property. 
H. Bila, V. Jakubsky and M. Znojil