Ads still showing while campaign already finished

Hello,

I have installed simpleads-7.x-1.8 and working. Still in development but wanting soon to be on line.
I already updated to drupal 7.16.
The problem is the following:

1. I created a campaign called "One week" which has starting time: 10/18/2012 12:14 pm. It is a campaign by days and with 7 days for running.
2. Created an ad with -no starting time,
-this ad is active
-campaign: "One week"
It correctly started the 18th of october, but one week later the ad is still active as we are now in the 26th.

Is this the correct behaviour? Am I expected to put the ad not active by hand after one week?
Am I missing something I dont understand?

thanks in advance