Hello Fafalone
It can be good to have a break from software. I have not done much with these controls while you have been away, it will take a couple of days to get back into them.
To make a start,
The screen flicker is because the uclist (shellbrowse) control does a double update, first with the files first, then with the folders first, hence the flicker. This only occurs (or is only visible) on folders containing a lot of files and subfolders.
I select a folder in ucTree, this execute "ucList.BrowserOpenItem ucTree.SelectedShellItem" and this gives the double update. This is confirmed by putting a debug.print in "ucList_DirectoryChanged".
I think this is intrinsic behaviour rather than a "race condition" between ucTree and ucShellBrowse.
Interesting observation problem does not occur if I set uctree.MonitorDirChanges = false
.....more in a day or so