zero-point energy correction

Dear Friends:
 It is my understanding that electronic energies from good (or high) quality
 QM calculations are usually modified by addition of zero-point energies, for
 example, to compare two isomers. I believe that zero-point energies are
 normally obtained from relatively low-quality (for both theory and basis)
 frequency calculations. This makes sense only if zero-point energies (unlike
 the electronic ones) are not critically influenced by the quality of the
 calculation. Is this true?
 Dmitri Goussev (Gusev), Associate Professor
 Chemistry Department
 Wilfrid Laurier University
 Waterloo, Ontario
 Canada N2L 3C5
 Voice: (519) 884-1970, ext. 2736
 Fax: (519) 746-0677
 E-mail: dgoussev()at()