Vista modems

The saga continues...
I have an old 'green frog' Speedtouch ADSL modem that is not going to have Vista drivers as part of the 'throw away your old junk, buy our new junk' drive. So I bought a cheap Zoom ADSL and downloaded their just out of Beta Vista driver. The install notes were long and if followed exactly worked.
Except that the line kept dropping. I tried this and that and the other, until one day I plugged into a different USB port... and the dropouts stopped.
I poked around in Device Manager. There are two USB Hubs on my machine, one 'full speed' the other 'high speed'. That must mean 1.1 and 2.0 USB. I'd switched to 1.1 - the slower connection!
The Data Rate meter says I'm not losing out, so I plain don't understand this one. I have the current Speedtouch modem on its way and its Beta driver ready and waiting, but I may have wasted my cash on it.

So all I need now is... more memory. 1Mb plainly isn't enough, Civ IV and Vista start to fight over memory around 1950 game time. Eve isn't bothered, it used to memory leak but this has been stamped out.