BUG #1586: Rollback of installation during a silent install with -qn option

The following bug has been logged online:

Bug reference:      1586
Logged by:          Preethi
Email address:      preethi.subramaniam@wipro.com
PostgreSQL version: 8.0.1
Operating system:   Win 2K Pro
Description:        Rollback of installation during a silent install with
-qn option
Details:

Hi,
 We are installing Postgres as part of our product. We use msiexec.exe to
launch the postgres installation. InstallScript ( which is the script
wriiten in InstallShield) is used to launch the msiexec and pass the
postgres msi - postgresql-8.0-int.msi as it's cmd line parameter.
  The following is the command line parameter for the postgres msi : /qr
INTERNALLAUNCH=1 DOSERVICE=1 ALLUSERS=[ALLUSERS] ADDLOCAL=ALL
SERVICEDOMAIN=%COMPUTERNAME% SERVICEACCOUNT=postgres
SERVICEPASSWORD=pOST!@gres SUPERUSER=postgres SUPERPASSWORD=pOST!@gres
BASEDIR=F:\POSTGRES.
     The installation works fine with the /qr option.It shows the progress
bar. However, I want the installation to be a completely silent one. So I
give /qn option. In this case, files get copied but then it rolls back.
    Note : There is no problem with the username,p/w and privileges as it is
the same given to both /qr and /qn option.
    Please let me know how to correct this.

Thanks,
Preethi