One of the things I do if I know I'm going to be distracted/tied up is to hit something useless, like reopening the same subpage or something in a new window. It resets the time clock.

But... I agree, it should be 30 minutes. And WTF with having to change your password every 30 days? My Bank of America online banking password has been the same for 17 years (no joke) so if it's secure enough for them, it should be secure enough for CCBill.