I was successfully working with node_import, version 5.x-1.2 (Drupal 5.3) to import CSV files. Recently, I've upgraded to 5.x-1.6 (in order to make use of the i18 patch to set imported content's language - see issue http://drupal.org/node/267555). Unfortunately, after uploading the CSV file the preview page gets all of the preview values wrong. If I try to advance to the final step of import the process fails (in my case the date value was wrongly imported from some text - I did see that the values for the date field were wrong even in the preview step). I noticed that just about all of the preview values were off.