I think you're confusing some terminology here.
Auto cron != cron
Auto cron is intended to run when you log in. It's based on admin activity. This is why the ticket does not get created until you log in. That's exactly how auto cron is supposed to work.
Auto cron is not really the best option. It's there for people running osTicket on systems in which they do not have access to crontab (most hosts provide this access, but not all, so auto cron is there as a fallback in those instances).
Cron us set up in crontab on your server, either via the command line or cpanel, or what have you.
You need one or the other, not both.
If you have cron jobs set up via crontab/cpanel/whatever control pane your host uses, could you please post that info here?
As for why it worked before and not now, without seeing the installation, I'm really not sure.
Also, since you're using cPanel and therefore have the capability to do so, the best option for your situation would actually be e-mail piping, not polling.
You can get instructions on how to set that up here: http://osticket.com/wiki/Email_Piping(http://osticket.com/wiki/Email_Piping)
I'm actually on vacation right now, so I don't have access to a lot of things and don't have a lot of this stuff with me, so please forgive me if I'm overlooking something or repeating something you've already done. :)