Are you trying to import from a csv/txt/excel file?
If so, a possible reason for not seeing the Field Names on your Left Hand side of your import mapping box is if the Field Names are NOT the first line in your import file.
My apologies for not clarifying this point. This is an FMP to FMP import. I understand that if it is an Excel or other type of file the field names will appear in the first record.
Using Filemaker 11 Adv on a Windows XP SP3 system, I don't see any change between Filemaker 10 and 11 in this dialog.
The source and target field names are listed. I don't see the data unless I click the >> button--which takes me to the data from record 1 of the source file and I can click << to get back to the list of field names.