Question about BASE graph charts

In BASE (basic analysis and security engine) for Snort, when I click on graph alert data, and then enter the variables to create a chart, if in the 'time period' drop down menu, I enter anything (1 week, a day, etc) and then press 'Graph alerts', I get a chart without IP addresses. However, if I leave the 'time period' dd menu set to 'no period', I then get the Ip address information in the color chart legend.

Why is this? Why can't I give it a time period and get the Ip address color chart legend like I do when I do not set the time period?

You may have better luck in a "base" or "snort" forum.

Well, I posted this question over at the BASE forum too, but just curious if anyone here knew why that was.

Thanks.