Two windows, both based on the same original.
Both have lists, but one have a different column, both have the same dates (start-end).
I have to take the unique data from one window to the other.
When I scroll with the TouchPad to a certain date and that window is not frontmost, when I click in the Row I want to copy something, it scrolls.
The Listbox in the other window (the Listbox in the non frontmost window) scroll. You target Row for 1949-04-28 and get Row for 1949-01-12 selected. Strange.
This happens on a consistant way.
Am I the only one with that ?
Nota: if I do the same, but on the window frontmost, no bug.
I already had that, but not noticed the bug appearance: only when the “target” window is not frontmost.
Compiled with 2015r1
Running on El Capitan 10.11.6 (15G19009)
Finder, Firefox (58.0.2 (64 bits)) and TextEdit (1.11 (325))
WiFi ON and connected
Power OFF / Battery ON
Work-around (but slow): I use the Search feature.
I found a bug (interesting feature) in my Search window: if I do not close the window, the search is always done on the first window I was searching originally.
This, is something I never think to test !
But in the current case (way I use the software), I am happy !
I continue to use the brand new project (now I use the compiled application).
I am adding some text in a Column, depending on a date column.
I am getting the same behavior: my application window with the Listbox is not frontmost when I move the Listbox Rows to get the date I want, and when I click in he Listbox to the Row I want to add what is in the Clipboard, I get a scroll (Bad boy Listbox) and I have a scroll, the selected Row is not the one I intended to click on !
Drag and drop works fine: select text in Firefox (the frontmost application, last version), press the alt key and drag and drop the text (I coded it that way); the text falls in the right Cell of the right Row (most of the time excepted when I am goofing 
).
Am I still the one to have that (to do that and get this behavior) ?
Edit: typo.
The best thing to do is upload a little demo project showing the specific problem so others can test it on their systems and check that your code isn’t doing something odd. You might get a little more feedback then 
As is, either no one experienced that (or no one want to chime in) or the bug is mine.
I will try to take time to do that.
Thank you Julian.