Another thought...
The import function is error prone, actually the import file is prone to user error, and the imports crap out with cryptic messages.
A better option is to use the API and write customer details directly to the views.
Record a macro while you add a customer to see how this is done, you need to filter out a lot of the junk that is recorded in teh macro.
I do many integrations like this and it is way better than messing around with import files.