Hi Amesika,
What file format are you importing from? I think what's happening is that one column is being treated as numeric instead of text, and therefore only accepts numeric input. If you're using CSV, Wizard uses the value in the first row of data to decide whether the column is numeric or not. If you're using XLS or XLSX, Wizard will examine the cell formatting. So "18-40" is being treated as text, but "100" looks like a number so Wizard assumes the rest of the column is numbers. Does that make sense?
Evan