For well over ten years, I (and other developers with the same configuration) have been experiencing this issue with Cygwin-X in multi-window mode with Java AWT apps. The issue is simply that the first time (and only the first time) certain AWT dialogs are dragged to move them, they snap back to their original position. The problem exists across JDK's, computers, cygwin versions, fresh installs, and everything I've tried. This can easily be reproduced by compiling (javac) and running (java) the attached trivial AWT code. If you get this error at runtime: Exception in thread "main" java.awt.AWTError: Assistive Technology not found: org.GNOME.Accessibility.AtkWrapper ...then you need to do these steps: edit /etc/java--openjdk/accessibility.properties, commenting out the line that reads, assistive_technologies=org.GNOME.Accessibility.AtkWrapper The attached program will demonstrate the issue. Also attached are (shortened) cygcheck output and the XWin log.