I tried the advice, but failed to see any improvement. LAYOUT_FIX_HEIGHT did not work, and cbo.children[0] refers FXWindow, not FXTextField, where killSelection is defined. I must have found a weak spot of FXRuby. The combobox is used for selecting a string in 90% of all cases. The default behaviour of FXComboBox is text editing and substring selection. I've tried to find the source code, but failed. Christer -- Posted via http://www.ruby-forum.com/.