My connection hangs after a peroid of inactivity

hi (again)

If i leave my ibook downloading overnight, i wake to find that it has hung. the connection appears active but the download progress bars and transfer rates are stuck, i try to disconnect and it just spins that crappy colour wheel at me and does nothing.

my connection is set not to disconnect etc etc and at first i thought it was something to do with the screen powering down, but i set everything to stay alive just to test and still the same problem.

im guessin its usb latency as im using an alcatel speedtouch 330 usb adsl modem (at least thats what id blame if it were a wintel box)

any ideas? its nothing too major but i would like to be able to leave it downloading all night

jt

and in case you need to know its a UK ADSL 1meg connection via an alcatel speedtouch 330

heh i work in tech support for an ADSL company and could probably fix it on a winblows box but im a n00b switcher and macs aint exactly my strong point (yet)