Occurs on Linux, does not in WinXP. Occurs at least with Metal and GTK+ look and feels. Consider a field with a path to a file, e.g. Settings / General / Web browser / Use. Provide there a path to file, with the following specific: . The file is in directory where a lot of files are placed, like /usr/bin. . The file is not at the top of file list in path completion, i.e. its name starts not with "a" or "b", but with "f", "h" or better "x". Open file chooser. Current file is preselected there. But file chooser scroll pane (with tree) is shaking, twitching during several minutes. Then twitching stops. It looks like some re-calculation of tree node position in scroll pane happens many times, and every time nodes are slightly moved. It may relates to file nodes "expansion": removing of "plus" sign (useful for directories only) against file nodes. When all "plus" signs are removed, the shaking stops.