有可能是对于php config误操作造成：
Hostmonster PHP Configuration
If you are not familiar with these options, do NOT change them.
This can cause all PHP scripts on your site to stop functioning if misconfigured.
NOTES:
# If you have custom handlers specified in ~/public_html/.htaccess, changing these settings can overwrite them. If you are not sure, make a backup of ~/public_html/.htaccess before changing settings.
PHP5
All files with the extension .php will be handled by the PHP5 engine.
Current, most reliable and best performing version of PHP
PHP5 (Single php.ini)
Same as PHP5, but all subdirectories will use ~/public_html/php.ini
PHP5 (FastCGI)
All files with the extension .php will be handled by PHP5 FastCGI processes.
FastCGI for PHP makes all your PHP applications run through mod_fastcgi instead of mod_suphp. This eliminates the overhead of loading the PHP interpretor on every hit. Since it is always in memory ready for the next hit, the responses will be generated faster.
NO MODIFICATIONS to your existing PHP applications will be performed so you can easily enable and disable it at will.
# Questions? click question for more info What are the benefits of using FastCGI for PHP with your hosting account?
# What are the potential problems with FastCGI and why I might want to disable it for PHP?
# What are the differences between the options?