ALE-130 USB ADSL modem settings

hey all...
i'm using an ale-130 usb adsl modem and it works fine.
the default setting is using RFC 2364 PPPoATM NULL ENCAPSULATION which is fine as long as i don't discconnect from the internet.

say i connect to the net and then use emule for a coule of days - everything is fine ,but if i want to disconnect the dialer just hangs..!!!

i did a little test and changed the modem settings to PPPoE - after a day or so i was able to disconnect without a problem!!.. but if the computer is on for about 2 days i get a blue screen of death saying "driver irql not less or equal with ndis.sys in win xp".

i changed the settings to the default of course, and the blue screen is gone but that means that after the modem works at full capacity (uploads & downloads for a day or so) i can not disconnect properly because the dialer hangs.

any solution ???