IE6 and sessions

Hi, I am having a few users who have 'upgraded' to IE6 saying that they are being booted out to the main page of my site AFTER loggin in. They tell me that they have set IE6 to accept all cookies, but there is still a problem. Of course when ever they click on one of my menu options in the member area it checks to see who you are by using a session variable. I append =SID to all my strings, so actually if they move their IE6 slider to 'Accept No Cookies' the automatic feature of PHP kicks in and appends the SIDs to the URL's. This has really got me stumped as I seem to have no problem ( I even upgraded to IE6 to check it out ). out of my 2900+members only 2 are having these problems. Anyone heard anything about this? Or am I going crazy Peter Mail Meld http://www.mailmeld.com