XP Boot Problems PART TWO

Archived from groups: microsoft.public.windowsxp.general (More info?)

Hi all
Advice from my original post prompted me to upgrade my psu, now installed
and working fine.(thanks Malke)
My boot problems however are still present. The problem: Initial start up
fails, reset/reboot brings about a loop: post, memory test, drive detection
etc. then safe mode, last known good, normal, start up options appears. At
this point we start again, this can go on for any length of time. Selecting
any option has no effect. Switching off and then on again also does not alter
proceedings. Start up then occurs at total random. Once running reboot and
switching off and on work with no problems. also performing a clean boot
returns no obvious (to me that is) problems.
defragmented, spyware free, no virus, chkdsk fine.

This boot problem only seems to happen when the system has powered down and
been left off for a length of time.
I would be grateful for any ideas. Many Thanks Nij
PSU: Antec 400w Smartpower SL400P
XP Pro with sp2
micro ATX motherboard MS6367, award bios v6.00 PG, nforce 420 chipset
AMD Athlon XP1700+ 1.4GHz
1.00GB DDR Ram (PC2100)
hard drives: Samsung SV4002H (40G)
Seagate ST320082A (200G)
CD-RW: HL-DT-ST GCE-8240B
Toshiba dvd-rom SD-M1612
NVIDIA GeForce4 TI4200-VTD8x 128MB DDR (running at 4x)