Key event at dialogue is not accepted when pressing esc + f11

Symptom:
Key event at dialogue is not accepted when pressing esc + f11 simultaneously

Environment:
OS : Windows 7 SP1 64bits Japanese
JDK : 6u91

To reproduce:
1. $ /jdk6u91/bin/javac EscDialog2.java
2. $ /cygdrive/d/jdk6u91/bin/java EscDialog2
   A panel shows up
3. Activate the panel of 2 (click the frame of the dialogue)
4. Press "Esc" and "F11" keys at the same time
5. A dialogue with "dialogue" title appears
6. Press "Esc" key to close the dialogue in 5
7. Repeat 4 - 6 continuously

When a dialogue does not accept the key "Esc" at 6, the issie is
reproduced.