I had been having problems with PIE being slow and with it forgetting logins (e.g. when clicking a link from the AximSite new posts search I would not still be logged in when the forum window opened)

Even clearing the PIE cache and cookies didn't help. I used Resco Explorer to find "aximsite" and found two places holding cookies and cached files. I deleted everything manually. Surfing is now much faster, and my logins now stick.