Strange results of CURRENT_TIMESTAMP

Hello,
   During repopulation of the database (using the results of the pg_dump
program), I spot two strange things:

- fields defined as TIMESTAMP DEFAULT CURRENT_TIMESTAMP sometimes generate invalid format of the date, for instance:
 2001-02-10 13:11:60.00+01 - which follows the records                             2001-02-10 13:10:59.00+01
 Which means, that the proper timestamp should look like: 2001-02-10 13:11:00.00+01

- I have a float4 field, which contains the value 3e-40 (approximately). I know it's there - the queries return it
withoutany problem. Problem occurs again when I try to repopulate the table. Having such a value in a line generated by
pg_dump(in form of COPY from stdin) I get the error:
 
 Bad float4 input format -- underflow.
 When I redefine the field as a float8 everything works fine. But why does it occur during repopulation - when in fact
sucha value did exist in the table before the table was drop.
 

I'am running Postgresql 7.0.2
            thanks for help
                    Mark