Just have a quick search and try the instructions, after all isn't the usb 2 supposed to be backwardly compatible??
There are also a few similar (to the search results that you will get) threads at
here the replies don't tend to be as quick but, they are distro specific.
Oh, and I should also say that you could try upgrading to 9.1 - if you got yourself a "boxed set" then the driver etc for speedtouch modem's is already compiled into the distro, and it should be just a case of configuring it.
regards
John
p.s. I actually got shot of my speedtouch (that I managed to get going under 8.2 and 9.0) because as I dual boot, it used to really piss me off, having to wait for the modem to disconnect and then re-initialise between OS's. I now use a modem router device and an NIC card - with no waiting, delay or hassle most distro's would see the NIC on install and it takes the connection responibility away from the OS.