I have seen many users struggling with attributes with EP, myself included. This was a major requirement of a current project so I just had to get it working.
I read that uploading a "complete file" with basic info AND attributes was a problem, so I began with that.
My solution turned out to be quite simple and it works.
I created a new Excel sheet with only 1 set of attributes like this:
v_products_model v_attribute_options_id_1 v_attribute_options_name_1_1 v_attribute_values_id_1_1 v_attribute_values_price_1_1 v_attribute_values_name_1_1_1 v_attribute_values_price_prefix_1_1 v_attribute_default_1_1 v_attribute_sort_1_1 v_products_priced_by_attribute EOREOR
I then add each option and value on a separate line. A product with 3 options each having 4 values would be listed on 12 lines.
I removed all of these columns from my basic EP upload file.
This removed the confusion of going across dozens of columns.
Some of the columns I needed/wanted are not in EP, so I added them to the update.
I did need to modify the updates to "products" and "products_description" to not do updates if the attributes columns existed.
I am not sure if any other code changes were made for this change. If someone tries this and has an issue/error, post back and i will look through the code some more. Or I'll post my php file.
I am creating the file from a database containing my products so I have no need for the description, but it would not hurt anything to have it there. You count just begin with the basic file, remove the "basic" info and add the above columns.
I did try to just duplicate the complete product on multiple lines with a new option on each line. In theory that should have worked as EP should have thought of them as updates. This is where my limited php knowledge comes in. I suspect that an array is being built with a unique line for each model number, so prior lines were being overridden.
I hope this helps someone.
Jeff