Try to avoid getting suspended
It's rare but occasionally when the system does an unsuspension it doesn't properly re-assign permissions to the .htaccess file. If it happens, it's easy enough for someone with root to the server to fix (have to be root to change root permissions), but sadly it's not something you'd be able to repair on your own, other than trying to avoid being suspended. Based on suspension history, it either happened way back in march, or more recently in august.
Other than trying to not get suspended it's not something you have control over though; if it would happen again, let us know and we'll jump in and fix it