Short desc:
  running of notepad demo ( http://java.sun.com/javase/technologies/desktop/javawebstart/apps/notepad.jnlp )
  causes the requesting of earlier JRE version if we are using
 C:/Windows/System32/javaws.exe.

Application starts OK if we are using C:/Program Files/Java/jre1.5.0_XX/bin/javaws.exe
Issue can be observed on 2 of 3 WinVista hosts, no issue on 1 host.
It can be related to a lot of JRE install/uninstall/testing on hosts.
The WinVista installation where problem is not appears is relatively fresh.

JRE affected: any 5uX build/update since 5u10 ( ea, fcs, j4b, rev )

See comments for details.