COPY command WITH NULLs bug?

I recently upgraded to 7.1.3.  I was experimenting with a script to 
export data from FoxPro into an SQL file and multiple data files.  The 
SQL file creates the tables, indexes, foreign keys, etc, and calls the 
COPY command to load the data from the appropriate data files.

It appears, and I could easily be mistaken, that the COPY command does 
not allow NULLs into a timestamp field, even though the field is defined 
to accept nulls.  Actually, it appears that the behavior of the COPY 
command changed as I believe it would accept nulls in the prior release 
7.1.2.

In any case, I'm using the COPY command WITH NULL AS '^N'. And the 
datafile contains ^N in timestamp fields that could be NULL, but the 
command fails with an invalid timestamp error, referencing the first 
line that contains the '^N' null sequence.

Any thoughts?

Thanks,
Dwayne