Error 503 – "Service Temporarily Unavailable"

Using WordPress 3.0.4

Please help, I′m getting this error for too many hours now…

try checking your htaccess file, if you changed it recently it might be the problem.
also try consulting your hosting provider, it might be a problem with the server.

Yep, checked htaccess:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /dev/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /dev/index.php [L]
</IfModule>
# END WordPress

Can you tell there′s something wrong going on?
I′ll check if I have an earlier backup version

Situation was on server side. And it is solved now

What exactly was the situation on the server side?

And what did your host change to resolve it?

Thank you,
Adam

@adam:

The situation on the server side was that they had implemented an extra security feature, the mod_security rule, guess to prevent recent hacker attacks as they said.

To resolve this, I had to login to my domain hosting service and disable “Extra Web Security”, then the error stopped coming up. Though, it lasted 48hours+ to had this solved from problem detection to hosting support response… But it′s all cool now.
Thanks,
Hélio

Thanks for your response, Helio.

I was also able to resolve my issue by unchecking the “Extra Web Security” box within my Dreamhost hosting account.

Adam