Hope this is not too late...
Anyway, definitely sounds like a graphics hardware/3d issue. I'm no expert, but maybe I could point you in the right direction.
What graphics card do you have? If you have Nvidia, you need to make sure you have the newest nvidia drivers available and are using opengl. I've never really used ATI and may not be of much help there, but you could check out Ubuntu Forum for 3d support with either manufacturer. If you have an onboard (intel etc.) card you may have no luck. I couldn't get 3d acceleration with a X3100 on my Thinkpad

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Also, take a look at wine appdb to see if anyone with similar hardware has had success.
(Just google "wine appdb silkroad")
Good luck, Silkroad will run in Linux through wine with the right card/settings. Mine runs now but I have an aggravating white box around my cursor, and I don't like it when things don't work perfectly...
EDIT:: I googled the specs for your Dell Inspiron 1420 and it appears you have the intel GM965 chipset, which is the same chipset I mentioned earlier (X3100) if I'm not mistaken. I searched far and wide about six months ago for working 3d support for this card in linux and could find nothing, still being worked on. Unless they have come a long way in the past six months I don't think you are going to run this in Kubuntu....just use XP and not Vista and save yourself some trouble
