0. Have the "fade" desktop effect enabled. ("Verblassen" in de_DE)
1. Run "xmessage yo" from a terminal
2. Make sure the xmessage window is stacked behind the terminal
3. Hit Ctrl-C.
4. xmessage window disappears invisibly
4. xmessage window pops to the front and disappears
fixed in 4.9
*** This bug has been marked as a duplicate of bug 158262 ***