Curiouser and curiouser... that seemed to do the trick, at least partially as the designer code now reads: ... this.m_FilterTypeComboBox1.Items.AddRange(new object[] { "= (equals)", "<> (not equal)", ... "begins with", "ends with"}); ... However, this is quite strange, when I run the form the combo box lists exactly 2 set of the list when I scroll down using the thumb, however when I scroll using the arrow it only scrolls through 1 set. ie The combo box items are: = (equals) <> (not equal) ... begins with ends with = (equals) <> (not equal) ... begins with ends with but when I press the down arrow to cycle through the options it gets to ends with and the next item is back to the top of the list. I'm stumped! Thanks, Paul