import data won't work properly
 

I can import most information but I am having a problem with one particular
column. The column is formatted in the "General" type of format. I can
import numbers to it but I cannot import letters. All information, numbers
and letters, in the other columns will be imported properly.

I can go to the workbook I am importing from and copy the worksheet and
paste it into my workbook. It will paste all information (numbers and
letters in all columns) correctly.

What is wrong?