There does appear to be some unresolved
problems in this area, with no very clear solution, apart from matching
hardware & with a suitable version of the the Ubuntu software.

I couldn't see any settings relating to the wireless card. In any case if there was a problem there, it would also affect VISTA, which works OK.

I might just try that. I've got a spare copy of Ubi 8.04 on the laptop, so not the
end of the world if I manage to screw it up :-)

Tech-geek reported that updating to 8.10 solved his problem. This could
be the solution as my wireless card may have been produced at around the
time when Ubi 8.04 was being finalised.

As an new version of Ubuntu is due next month, I may just wait until
that is available. As my broadband is rather slow I normally get Ubuntu
an a DVD which comes with the Linux Format magazine, which is available
in the UK.