I got a Vodafone(Huwaei) HSPDA modem and installing it in linux was well, not a nice experience. I had ubuntu 7.1 in my computer and I had to install wvdial to get my modem to work in linux. That was not very difficult until I decided to update my system to ubuntu 8.04. Wvdial comes intalled in that version of ubuntu but strangely the modem would not work. I tried many things unsuccefully before i found an easy way out, upgrading the network manager.
If you are planning to use the vodafone HSDPA modem with linux my advise would be to update your OS to the latest version and then upgrade the network manager to 0.7.
In a debian based distribution such as ubuntu you can use the following urls to upgrade the network manager.
insert the above urls to /etc/apt/sources.list file and enter the command, ‘sudo apt-get update’ to update the update list. Then update the OS using command, ‘sudo apt-get upgrade’ or using update manager and the network manager would be updated to the latest version. Then making a connection using the modem should be straight forward.