Feeds CSV import error
Are you running the alpha-4 or the current dev version of the feeds module? There have been a number of tickets discussing the same error condition you are having with node_save on import that coalesced around this issue on Drupal.org with a resulting patch committed to the current dev branch. You can try downloading the current dev branch of feeds (almost a year older now than alpha-4) or applying the patch at #25 in the above issue if you don't want to accept all of the updates since the last alpha release.