I just installed Drupal 6.1 on my Ubuntu 7.10.
It went all fine,
but I'm having some trouble with relative paths:
Many people have had trouble trying to change the logo image,
this is due to the fact that when you upload an image in drupal, it stores it in other_dirs/Drupal_site/files/name.jpg,
so a lot of people (including myself) try to give the complete path to Drupal instead of files/name.jpg
After this the logo is corretly displayed.