Please see my reply on the 'fake email' thread. The email everyone got to upgrade F/W is causing issues. I have V3.03t as well on my HG532 (since the update a few months ago). Running the update tool it just says 'unknown router'.
I have reset the password back to 'admin' and the IP range to 192.168.1.1, (you have to do that as the tool is a bit 'noddy') but it still does not work. It is possible that 3.03 IS the latest version; I read in a previous thread that the upgrade tool says 'unknown router' if the F/W it is trying to upgrade you to is the same as you already have (more noddiness ).