BUG #8672: pg_sleep function doesn't work as expected

The following bug has been logged on the website:

Bug reference: 8672
Logged by: M CHRISTOPHE NICOLAS
Email address: christophe(dot)nicolas(at)9online(dot)fr
PostgreSQL version: 9.2.2
Operating system: Windows Seven
Description:

A simple example :

Create Table tst_sleep(instime timestamp);

Do '
Begin
Insert Into tst_sleep values(Now());
Perform pg_sleep(5);
Insert Into tst_sleep values(Now());
End;
'

Select * From tst_sleep;
2013-12-09 09:23:54.012
2013-12-09 09:23:54.012

=> The Do execution last 5 secondes (ok), but the 2 rows are inserted as
same time.