I fix the problems which arise with every Ubuntu release (and in between) for a friend at work whom I’ve put onto Linux. This upgrade to Lucid has meant a number of issues *yawn* but the most annoying was that plugging in his Huawei E220 USB 3G modem was only sometimes detected (every other time it’s just a USB CD and USB memory stick). It was working perfectly on Karmic and on Jaunty (with some hackery) before that.
The solution was rather simple in the end, just load both usbserial and option kernel modules on boot (add to /etc/modules). The kernel will then switch from CD-ROM and detect ttyUSB modem correctly. If you’re having problems with your device not working, try this.