Key changes were made by Ryan Bayne yesterday in the area of reading CSV files.
Users are now encouraged to ALWAYS select their files separator, quote and even enter the number of fields/columns in their file. This is far more reliable.
The interface and functions have been changed to reflect this. It is a different direction in the area of reading and handling CSV files. The interface looks good I think and Ryan told me he had total success testing a tab separated file with single quotes. That file would not work properly using PEAR CSV prior to the changes.
PEAR CSV is used in other CSV import plugins for WordPress however it should not be relied on. After a week of extensive testing, fget approach and counting the number of separators plus quotes in the header row is far more effective.