I have auto-census running and it runs every 30 minutes or so. I also run UniUpload - set to upload every time the save file changes. I'm sure you don't need me spamming the site every 30 minutes, so I had a dig through the lua file and found the line that checks how long it's been since the last auto census. I think this is in seconds (1800 = 30 minutes?) so I changed it to 3600. Since then I have yet to play for more than an hour to test to see if this works!
Having to edit the lua file is a little scary (I'm only a trainee geek - I've not earned my pocket protector yet!

I would have looked at doing this myself, but that is far beyond my abilities.