I use Lazarus 1.6.4 from 2017-04-08 FPC 3.0.2 SVN 54278 x86_64-win64
When i close all (Editor-)windows (ctrl-F4), I notice a flicker in then MenuBar of the IDE.
It stops when I choose (click on) a menuitem. And starts again when the menuitem is closed.
It also stops when I open a file from the project in the editor, and starts over when closing the file.
I can confirm this behavior on the released lazarus.exe and on the recompiled version.
Same behavior on another computer.
Can someone confirm this ?