dropdown is closing quickly without any action when tried to open it. it is a motif Xt library based application. there is textboxes present in the same window and it have a call back functions for focus and losing focus.
and in that function xtGrabkeyboard is called on focus callback function and xtUnGrabfunction is called for losing focus function.
the function used to create the combo box is xmComboBoxWidgetClass
by removing the xtUnGrabfunction in losing focus function . it is working fine what may be the reason for it or is there any latest update for the these function in Xt library