Date issues between versions of PostgreSQL

Good Afternoon,

We have upgraded from version 7.1.4 to 7.2.1 and have noticed some issues
dealing with the way dates are handled (still tracking this down).  One of
the errors that we are seeing comes from this statement--

select to_char (hiredate, 'MM/DD/YYYY') from employees;

The error we receive is--
ERROR:  Unable to convert date to tm

This worked fine on the older version of the DB and it also works on other
date columns in the same table on the new version, although the year in that
column is the same throughout the table if that makes any difference (our
birthdate field uses 2002 as the year so nobody gets offended trying to find
out their birthday).  Have any of you run into this situation?

Thanks,
Jay Schlenker
GUI/Web Development Team Leader
RD&Q--Mandan, ND
National Information Solutions Cooperative