my guess it that it exists in the data but just not displayed in Mgnt studio results.
If you open the table not query it you should see those characters.
Other thing you could do to confirm is check for these in your where clause.
Where myField = Char(14) or whatever the ASCII code is for the characters you are seeing.
or display the value of the non-print characters
- ASCII(myField) (returns ascii value of first character in field)
that should clear things up.