7u21 update fails with 'files could not be downloaded' when user not an admin after entering password at UAC prompt

A DESCRIPTION OF THE Bug :
Normally I am logged in to vista as standard user but not as admin.

Every time Java reports that an update is available, I am asked for the admin password of my system.

If it is given, update procedure starts but is aborted because " download of installation files " fails.
When logged in as admin, download and update are successful.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
either display a message to login as admin before updating java (brrr, then we don't need standard users)

or:

Store the temporary download files anywhere but NOT in the admin area where a standard user has no rights!