2 win xp users and fn+sleep usage

[garnet]

Hi
I have 2 users in my xp sp2. Admin (at admin level) and user2 (being a user level only). User2 have read, execute, list folder on windows and program files folders.
When I am logged in as admin pressing fn+f4 (sleep) will put the laptop to stanby
When logged as user2 - fn+f4 doesnt do enaything. Going through start>shut down>standby works.
If I elevate user2 to admin levev group - fn+f4 works.

It is clearly some privileges issue, but what exactly? I know power options are user specific, but how can I make fn+f4 to work for a user priv. level?

Thanks