I have a generic Pentium 3 800MHz, 256Mb, MSI 6154VA motherboard with Windows XP SP2. When I shutdown the computer it powers off but leaves the CPU fan running and the front panel LEDs are dimmed but still on. Power cycling the switch at the back on the power supply turns the system off completely. Is this some kind of standby or soft power off mode? I've reset the BIOS but it still happens. Thanks, Jonathan