sometimes means that you may have to visit the site/s on a daily basis?
probably your browser has a setting to control this?
I keep several cookies that are for sites reqiring userid and password. For some reason,and it's not consistent, after 5 or 10 startups or restarts, someting will delete these cookies, requiring that I put in userid and password the next time I go to the site. I use CCCleaner but have the cookies box unchecked and as mentioned it happens sporadiclly.
I scan regularly with AdAware, Spybot, Microsoft Anti Spyware, run Win Patrol, Spyware Blaster and Spyware Guard. I scan regularly with AVG and use Zone Alarm.
It's no big crisis, but I am just wondering why this happens.