Problem with Creative Graphics Card

I recently upgraded from an Asus GeForce2 GTS to a Creative FX 5 5600 Ultra
(128Mb)
When I plugged it in, I started to get some interesting effects

Every so often, the monitor would appear to go into power saving mode.
There seemed to be no way out, other than the restart the system (even the
old 3-finger salute didn;t seem to work)

I ran DXDiag and ran the "Test Direct3D" and "Test DirectDraw".
It was when these tests were run, the card sent the monitor into power
saving mode
Therefore, I suspect, the problem has something to do with whenever the 3D
engine is kicked into life,

Decided to run Final Reality, and came out with a score of around 5.6.
This didn;t cause me too much concern until I compared that with a friend
who is running an 3-4 year old ATI Rage 128 16Mb - he was scoring in the
high 9's.

At this point, I decided to contact Creative to see if they had any
suggestions.
They had several suggestions, but the only thing that seemed to make the
system any more stable was to turn off AGP Fast Writes.
Final Reality scores were still very low, so I plugged the card into my
friends computer - and got simialr scores. 5.7 (ish, can't remember exctly
now - certainly not good scores!)

At this point, I RMA'd the card and got a new one back
Plugged it in all expectedly, hoping to see a drastic improvement - but,
alas, I did not.

At this point, I started to conisder the fact that, perhaps the card wasn;t
the problem.
I did some digging around on some forums and started to find a fairly
generic problem.
It seems that a LOT of people running with VIA chipsets and trying to run at
AGP 4x seemed to be having problems - but no one seems to have a definitive
answer.
I downloaded, as one of the postings suggested WCPUID and discovered that,
when I had AGP Fast Writes disabled (for stability) I was only running at
AGP 2x
If I turn AGP Fast Writes back on, I can get AGP 4x, but the system has a
tendancy to fall over (or, at least, go into this strange power saving
mode).
I did manage to keep the system up long enough in this mode to run FR
again - but the scores still seemed to be around 5.7-5.8

Can anyone advise whether they think it is the card at fault (I find it
difficult to believe I have been sent two cards with exactly the same
problem), or whether FR is not reading properly.
Has anyone got the VIA Apollo 133 Pro chipset and a Creative Card and having
the same problems.
Has anyone got that combination, but doesn;t have the problems - if so, what
did you do?!?!?
Anyone got an ABit m/board and having the same problem with a different card

I have rung Creative again, and the only thing they have suggested is some
configuration with my system (i.e. they don;t think it is the card) and have
suggested upgrading the PSU.
Mine is currently, only 300W - but to test this out, I unplugged everything
I could (leaving only the two HDD and the card) and it didn;t seem to help,
so not convinced by this

Any help greatfully appreciated.

Martin

System Details:
ABit VP6 motherboard
2 x PIII 1GHz CPUs
2 x WD1200JB 120Gb HDDs hanging off the onboard HPT 370 RAID controller
(RAID 1)
1 x IBM 60Gb drive hanging off the other RAID channel
1Gb RAM
Windows XP Pro SP1

Have installed all possible patchs from Via / Creative / Windows.