Hello, I'm new at RSS. I need help to understand how RSS works. Basically I have tried creating a RSS feed with a program that will update the RSS feed every 15 minutes (in my case an XML file). I have validated the feed using http://www.feedvalidator.org/ and it passed the validation. Then I added my RSS URL into Google Reader + Internet Explorer 7 RSS reader. Google Reader displays the items in my RSS feed correctly at the very beginning after subscribe, but then even though the XML file has been updated, it doesn't show up there. Internet Explorer 7 reader displays only one items from my RSS feed correctly at the very beginning after subscribe, but same with Google Reader, it doesn't show me any update. Isn't reader like Google Reader/ Internet Explorer 7 RSS reader supposedly will display update? What is it looking for to detect updates? Is it the number of "<item>" tag or something else? Thanks in advance for all the help.