Im****ting Data Error

I am im****ting txt data into an existing table with no primary key.  I get
an 
error saying:

“Microsoft Office Access was unable to append all the data to the table.

The contents of fields in 0 records were deleted and 87 records were lost 
due to key violations.

*if records were lost, either the records you pasted contain primary key 
values that already exist in the destination table, or they violate 
referential integrity rules for a relation****p defined between tables.”

My trouble is there are no existing records in the table I’m appending
so 
the primary key values don’t already exist and the table is not linked
to any 
other tables.  Any help you can give me is greatly appreciated.  Thank
you.