minor power option problem

Hello, WindowsXP Home sp2, non-network, single user, 56k modem.
Use a screen saver(3d flower box) set for 15 minutes. Monitor power
option set to turn off at 20 minutes. After reboot power option will
not work unless it is reapplied, it shows as set for 20 minutes. Has
always been set this way, problem started about a 7 days ago.
Power Options.
power schemes "always on"
turn off monitor "20mins"
turn off HD "never"
sys.standby "never"
Advance tab. power button "shut down"
Hibernate "not checked"
Take Care.
beamish.