Did you take a look at what's inside the .htaccess file? Is it consistent with Mys v1.3.3's .htaccess? Also have you contacted your host for this? Perhaps there's some misconfiguration from their side, it's tough to tell.

Hello!

I have a same problem with login to my admin account.

The link to the site: http://altarin.freehost.int.ru/
I checked, the registration is working fine, I can log in with registred account, but I can't log in with my admin account. Have no idea what to do.

I sort of solved problem.
I changed usergroup for my working test account, and it finally works.
But I don't understand why my fisrst account didn't worked :C

Perhaps there is a tiny bit of issue with your password. Have you tried resetting your password for the first account?

Yep, I cnanged it right now, it's still not working.
Also, i tried to get email with new password (as if I forgot it)
I didn't got any emails at all.

I'm sure problem in not the password or so. I have a hard installing, and I was need to rewrite it several times, until I did all steps correct, so may be there is a reason.

This is exactly my problem, I came here to see if there was a thread on this... I didn't get an email either.