Thanx for your reply
Sorry, my message earlier may have been a little confusing ... I do want to keep Ubuntu, but it is based on the 'woody' debian dist (i thought) which the new version of clamav does not support (as far as I know) ....
I did try to install from the 'sarge' repositories but got a message like
' No public key available' when trying to refresh apt-get.
Then I realised that Ubuntu 'hoary' had clamav within one of the default/commented-out sources in /etc/apt/sources.list
I installed that version but it won't let me update using freshclam ... said my version of clamav needed to be updated ... I decided to install the clamav-data file instead of freshclam, and it does not recognise as many viruses and trojans as freshclam.
I hope this is a better description of the problem.