1) Do you have any GSDs actually working in 10.04?
yes. I have two GSDs (a Denon amp and a JVC beamer) working. Otherwise I would be dead by now.
If yes, then 2) In webadmin -> wizard -> devices -> Generic Serial Control Devices..
under Device Data, in the COM port dropdown, what options is it giving you? Mine is showing the correct PCI address, but not the right /dev/ttyUSBx address.
It is showing /dev/ (pcixxxxxxxx) for each of my AV devices. All of my devices are connected via USB2Serial adapters.