Environment : JCK1.5a b11 - JCK-Runtime-15a [ runtime & interactive mode]
Java Tested: 1.5.0_08-ea-b01 and 1.5.0_08-b02
Windows Vista_X64 Build 5384

Failing Test Cases: javasoft.sqe.tests.api.java.awt.interactive.MenuTests
MenuTest 0001, 0002 and 0003

Observations:
The test 0001 is used to verify that a seperator can be added as a menuitem to a pre-existing menu list, which passes ok. The test also has a 'Reset to inital state' button.
However I have observed on Windows Vista that when you click this button the test frame becomes frozen, the user cannot interact anymore with it. The only way to get the test frame back to normality is to maximise or minimise it.
The same behaviour is seen on the 3 MenuTests 0001, 0002 and 0003.

I also tested on Solaris 10 and Windows XP Home where I could not reproduce this issue.

I have attached .jtr for full details.