I haven't bothered you for a while and I'm happy to report both extensions are working perfectly. They make me sleep better at night.
The problem I'm having may be due to the remote site's host, Hostgator. I'm trying my first frontend backup from SC Control Center (on a site hosted on a different Hostgator account) to the remote site. The site backs up fine locally, and Control Center accesses it just fine. However, when I try the backup, this is what happens. First I receive this message, which is what I'd expect:
This process may take A LONG TIME, especially in shared hosting environments or if you have too many backups running at the same time. You can set your email in Akeeba Backup under Options -- Front-end backup and you will be notified once backup is finished. If you already have configured your email in Akeeba Backup, you can close this window and do other things.
But then it returns this about five seconds later:
Your browser sent a request that this server could not understand.
Additionally, a 400 Bad Request error was encountered while trying to use an ErrorDocument to handle the request.
That message can be caused by several reasons; launch the task again and see the Apache's error.log (if you don't know where is it please ask your hosting provider). There you should see what's happening.