>yeah.. really seems that.. in fact. this was the stuff that I've been searching for.. But, I didn't found any option on IE preferences.. That give me a way to use two different cookie sessions..
>
>On that moment.. I just had made logof in another site (and shutdown the other window).. now that I am noticing..

See if under Security, Custom, Miscellaneous, that Userdata persistence is enabled. Otherwise, this may be intercepted by a tool such as Norton Internet Security or similar.