Have you tried posting in the Xandros forums for help getting your modem working in Xandros?
No, I searched the Ubuntu & Xandros forums and found post where they got the modem to work. Both OS have the drivers....the hard part is getting the OS to find the modem. I did everything they listed and no luck, SuSE found the modem right off the bat so I stuck with SuSE

When you're in Newbe stage and trying Linux for the first time, I don't think you should have to learn some advanced BS just to get hardware working.