Dear Dumitru,

did you use in your calculation the keyword 'density=current'? If not, then the discrepancy may come from the fact that you are comparing the dipole moments for ground state with the excited state.

Please see the manual page:

http://www.gaussian.com/g_tech/g_ur/k_density.htm

If you did use this keyword, then note that the checkpoint contains both ground and excited state WF and, the ground state WF is preferentially read by programs. If you need the excited state density for analysis, then I usually use the 'cubegen' utility to extract the density from formatted checkpoint (option Density=CI).

http://www.gaussian.com/g_tech/g_ur/u_cubegen.htm

I hope this will help.

Martin