Renamed Admin account, now I can't login.

[frog357]

I made a dumb mistake and renamed my admin account, now I can't login to access my site.  I tried the change password feature but upon login I receive a message about:
You were unable to login.  Please check your cookie settings.

I tried a number of ways to fix this on my own.
The only way I could regain access to my site was by going into the database and changing my username back to the old name and then resetting my password.  Once I changed my name, even resetting my password would not let me back in.  I'm in now but I think this is a bug or a user error can anyone verify?
Thanks!

[Tristan Perry]

How exactly did you change your username?

[andrea]

Did you already delete your cookies?