A couple of possible solutions:
you can turn off the ability to show phpsessid on all links in php.ini...
in the privacy options for your web browser, this can affect the display of a phpsessid.. somtimes you might block a site from accepting cookies and it will show the phpsesssid, and then when you allow cookies, it won't show it... but other time's a site won't be blocked from accepting cookies and will still show the phpsessid..
so if you can have a look at your php.ini file, and look at your privacy settings for your browser..
Hope it helps..