I cant say for sure about IE, I only remember the problem since switching over to firefox...

I logged in the way you said and it didnt work...BUT...I did some playing around and found that when I clicked on the BROWN Community button along the top of the page where the buttons go left to right, it doesnt remember me, but when I enter using the big BLUE button on the right side of the page where the links are top to bottom it will remember be...

the brown community button at the top (the one that does not remember me) has the link -
http://www.nonrev.net/forums/index.php?autocom=portal

where as the blue community button on the right (the one that will remember me) has the link -
http://nonrev.net/forums/