Access probleme on Chopin : 500 Internal Error

[fomalhaut]

Hello.

From yesterday, I can't access my web site regularly. Sometime it's ok, but now for example, I've the following message, after a long delay :

500 Error
An internal server error has occurred. Please try your request again momentarily.                             
File or directory permissions are set too high: Files should be 0644, directories 0755.
Problem with your .htaccess file.
A syntax error in a CGI script.

As nothing is changed on my site, I presume it's a servor problem.

Thanks for your intervention.

Regards

My site is http://fomalhaut.x10hosting.com/