The most likely cause is that iPage Hosting does not allow you to lock the root .htaccess file with 404 file permissions. You may be able to use 444 file permissions, but that would have to be done manually via FTP.
http://forum.ait-pro.com/forums/topic/read-me-first-pro/#root-htaccess-file-lock
If your Web Host does not allow locking of your Root .htaccess file (404 file permissions for your Root .htacces file) and your site has crashed then FTP to your website and manually change the root .htaccess file permissions to 444. If your site is still crashed/not loading then change the root .htaccess file permissions to 644. After your site is back up go to the BPS htaccess File Editor tab page and click on the Turn Off AutoLock button. This will prevent your Root .htaccess file from being automatically locked when you upgrade BPS, which will prevent a 403 Error from occurring on your website.