Problems with P4S8X-X & GeForce 4 MX440SE 128MB DDR

Hi,

I've just upgraded my PC and I bought a GeForce 4 MX440SE card and have
been having terrible trouble with it. The commonest problem is the screen
going black for a second as though changing resolutions or refresh rates.
Other times the screen goes blank and the monitor goes into standby mode but
the PC stays on and functioning. Lastly, the screen goes blank, then into
standby, then the PC reboots, and the HDD is full of errors on restart.

The other (related) problem is the screen goes blank and after a long
wait comes back in 640x480 4 colour mode. After rebooting WinXP reports a
driver error and after sending it to Microsoft a page is open explaining
about "Microsoft Knowledge Base Article - 293078: Error Message: STOP
0x000000EA THREAD_STUCK_IN_DEVICE_DRIVER (Q293078)". I've tried all
different driver versions and some a re a little better some a little worse.

This and the problems above occur randomly and are not reproducible by
doing any one thing.

Another thing is when I click on Advanced in Windows Display Properties
the screen blanks and "clicks" as though changing settings, is this normal?

I've noticed that the drivers being installed by default for the card
are for the MX440, where as I've got a MX440SE could this cause the problem?
(The Core & Clock frequencies are different between the two). How do I get
the nVidia install program to recognise the card correctly?

I'm wondering if my PSU is at fault as it is a 300W unit. I've done the
sums for Watts and Amps found on various sites and the conclusion is my
system draws 310W and 17A on the +12V line which is only supplying 15A.
Would this explain the problems? Do these figures sound right for the kind
of system I have (I'm not very up on the electrical side of PCs).

System Spec:
P4-3.06GHz HT 533Mhz
512Mb PC2700 DDR RAM
Sparkle GeForce 4 MX440SE 128MB DDR with TV Out
ASUS P4S8X-X Motherboard Rev 1.1 (AGP 1X, 2X, 4X, 8X) (On board LAN & Sound
both disabled)
SB Audigy Player Sound Card
PCI V.92 Modem
2 x EIDE HDD
1 x CD-R/RW
1 x DVD-ROM
3 internal fans
6 x USB ports (3 in use)
Winning PC case + PSU (includes 12cm E-FAN, 8cm I-Fan)
KB/Mouse

WinXP Pro

The new parts are: GeForce, M/B, RAM, P4 Case + PSU, so obviously it is
hard to narrow down what could be at fault. Nothing from my old system can
be used in the new to test it (or visa versa). All drivers/BIOSes are upto
date.

Sorry to be such a hopeless case but this is the first upgrade I've done
for over 5 years and things have changed quite a bit since then!

Hope someone can help,
Rob