If you are scrolling the sample list in the main interface, with the mouse wheel, and if you have your mouse pointer on the category combobox of a sample, both the interface scrolling and the combobox value change are occuring.
TODO: if mouse pointer is on a combobox, do not scroll the interface on a mouse wheel event, or scroll the interface but not change the combobox value.
If you are scrolling the sample list in the main interface, with the mouse wheel, and if you have your mouse pointer on the category combobox of a sample, both the interface scrolling and the combobox value change are occuring.
TODO: if mouse pointer is on a combobox, do not scroll the interface on a mouse wheel event, or scroll the interface but not change the combobox value.