BUG #5162: Admin can't connect and won't use port 5432

The following bug has been logged online:

Bug reference: 5162
Logged by: Charles
Email address: cnicol(at)mediasensorcorp(dot)com
PostgreSQL version: 8.4.1
Operating system: Vista Home Premium
Description: Admin can't connect and won't use port 5432
Details:

The installer forced me to use port 5433.
Admin launched, I could see the DB in the object pane, but I could not start
it. I had to use port 5433.

So how can I make it work with the correct port and start it?

It won't work.
I tried to open the port on firewall, but it doesnt work with the firewall
off.
I already tried the install with firewall off trick.
Not sure why it created a new User account on my login screen called
postgress either. Was that necessary?

Baffled. I am blaming MS and VISTA at this point.