drupal 6 to 7 site upgrade using drush_sup - how to download compatible drupal 7 modules
I would run through the site upgrade process with the --prompt-all flag set to see if anything strange appears. 

drush drush_sup will upgrade core and find good candidates for contrib modules, I think it'll even accept dev releases, but with a warning.

You could also pass in --auto to the command which will just do the defaults.

Source: http://drupalcode.org/project/drush_sup.git/blob/refs/heads/7.x-2.x:/README.txt