I did log support tickets with both gpotato and Allods.com.
Gpotato just said to reset password which I did but it didn't help.
Allods.com hasn't replied yet.
Guess I'll just wait and submit another ticket in a couple of days.
Thanks anyway.
It's probably worth sending them an update including the full address that gives you the 403 error - with that they can see the exact point of failure for the permissions.