Sounds like IE is caching the result. Try programatically changing the url of your HTTPService by tacking on a querystring parameter with a timestamp. So, change the url to http://www.whatever.php?ForceIEReload=20081022T11001234. Your PHP script will ignore the extra parameter, but it might force IE to not cache.
Here's a link that discusses IE caching and a workaround. http://www.howtoadvice.com/StopCaching Jared Langdon
