sites have completely disappeared

I upgraded all 3 websites to 3.1 two days ago. One (www.being-in-voice.com/blog) continued to work ok until about 10 minutes ago.
Another, http://www.blog.thundersmouththeatre.com would not allow me to login. I tried all the fixes suggested on the forum, it worked until I went to bed. In the morning it wouldn’t allow me to login.
The third, http://www.flloyd-in-voice.com, I didn’t do any of the fixes, but I did replace the wp-login.php file with a new one, checked that it was the latest version. That was when the website disappeared completely.
Now, without having done a thing, all 3 sites are inaccessible.
I just noticed at the end of the Sticky posting at the top of this section that there are apparently issues with IIS. IIS is what appears at the head of the addresses within my hosting server (ixWebhosting). I’d be grateful if someone could give me some information about what is happening and how I will know when the situation has been fixed, or indeed if there is anything else I can do.