Just verified this on another Slackware machine:
(this one is a HP Netserver LH3)
free4testing=# select version();
version
------------------------------------------------------------------------
PostgreSQL 7.3.3 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.2.2
(1 row)
free4testing=# select timestamptz('1901-12-13 23:59:59.999999');
timestamptz
----------------------------
1901-12-13 23:59:59.999999
(1 row)
free4testing=# select timestamptz('1901-12-13 23:59:59.9999999');
timestamptz
---------------------------
1901-12-14 00:19:00+00:19
Just let me know what you're interested in, if anything.
Best,
Frank.