I have just downloaded subtext 2.5 source code and manage to run it on Visual Studio dev server. The problem is that whenever I try to navigate to admin/.. it redirects me to login page and it's not accepting default login credentials that are, I suppose, haacked and password respectively. But I was unable to login to the site.
Subtext_Host table of db contains following entry:
userid= Haacked, password= sIHb6F4ew//D1OfQInQAzQ== salt=KrPog8xD4kKBwW35zBxxCA== email=haacked@gmail.com datecreatedutc = 2011-06-11 21:37:29.533
I also tried resetting the password as described here (scroll to bottom) but to no avail.
The password you have reset is the Hostadmin password, accessible via http://<yoururl>/hostadmin/default.aspx by logging in there you should be able to reset the password for the particular blog you are interested in.