Running A 'Distinct' Query Returns Some Results TWICE !?

I've spent hours trying to find out why a perfectly simple query that uses the 'distinct' keyword such as:

Select distinct(field1)
From tablename;

works fine based on eg. field1, but when running it on eg. field2 in the very same table, it returns 2 results (yet, only on some words!). Pls see example of result below:

Eg of a 'faulty' result: .....