Let me summarize up the story here (hope it's not too lengthy ;)

1. At 29-Nov-05, I bought a 2nd hand 10" monitor (Topcon VS-10S) from
shop. I intended to use it to connect my PII PC (P2L97

motherboard) w/ NVIDIA RIVA TNT display card & XP Professional
installed.

2. I could get normal VGA display from 10" monitor connected to PII PC.

Tested WinXP display setting: 640x480, 32 bit color, 60Hz vert. freq.,
PnP monitor (normal output)
Tested WinXP display setting: 800x600, 32 bit color, 60Hz vert. freq.,
PnP monitor (messy output)

3. Display output was turned into messy as I change the display setting
to value other than 640x480, others kept unchanged.

4. First posted message here.

5. At 30-Nov-05, I connected the 10" monitor to my Althon PC
(MP-7VIP-DR-LE motherboard) w/ winFast S610 AGP display card

(called it NVIDIA GeForce 2DDR in previous messages) w/ ME & XP
Professional installed in C: & D: respectively. Display

driver used that available from XP.

6. Replied messages here.

7. I booted the Althon PC into XP. Then I tried changed display setting
from 1024x768 to 800x600, display output turned into

a mess.

Tested WinXP display setting: 800x600, 32 bit color, 60Hz vert. freq.,
PnP monitor (messy output)
Tested WinXP display setting: 800x600, 32 bit color, 70Hz vert. freq.,
PnP monitor (messy output)
Tested WinXP display setting: 800x600, 32 bit color, 72Hz vert. freq.,
PnP monitor (messy output)
Tested WinXP display setting: 800x600, 32 bit color, 75Hz vert. freq.,
PnP monitor (messy output)

Note: above setting was changed by connecting PC with my Samsung
SyncMaster 151B LCD monitor then swapped connection to 10"

monitor after setting effective.

During the test, I've called the shop on phone, they reminded me to
make sure vert. freq. was at 60Hz.

8. Discussed case with Phil here.

9. At 1-Nov-05, I tried connect the 10" monitor to my 3rd PC, also a
PII PC (P2L97 motherboard) w/ WinFast 3D L2300 AGP

display card w/ XP Home installed. Display driver used that available
from XP.

10. I tested below WinXP display settings, tests failed.

Tested WinXP display setting: 800x600, 32 bit color, 60Hz vert. freq.,
PnP monitor (messy output)
Tested WinXP display setting: 800x600, 32 bit color, 70Hz vert. freq.,
PnP monitor (messy output)
Tested WinXP display setting: 800x600, 32 bit color, 72Hz vert. freq.,
PnP monitor (messy output)
Tested WinXP display setting: 800x600, 32 bit color, 75Hz vert. freq.,
PnP monitor (messy output)

Note: this PC was connected to NEC MultiSync V520 while changing
display setting.

11. I went to the shop again by 1-Nov-05 evening, the staff tested my
10" monitor at their PC, no problem at all at 800x600,

60Hz vert. freq.

I checked from XP display properties, they used Matrox Millennium 550G
display card with dual display output, one connected

to original Philips 105S monitor, another to this 10" monitor.

I asked them why will that happened. They had no idea. One guy
suggested me re-installed display driver (may be it's not

update). What a suggestion !!!

Finally they gave me another Topcon 10" monitor (called it NEW 10" MON
below).

12. I tested the NEW 10" MON at my Althon PC with below display
setting:

800x600, 32 bit color, 60Hz vert. freq., PnP monitor (messy output)

13. Suddenly, I remembered this PC also has ME installed. So I booted
into ME & ran the tests again. Test failed with below

settings:

Tested WinME display setting: 800x600, 32 bit color, 60Hz vert. freq.,
SyncMaster 151B monitor (messy output)

14. At this point, I almost gave up. I tried it again in my PII PC w/
WinFast 3D L2300 display card using below setting:

Tested WinXP display setting: 800x600, 16 bit color, 60Hz vert. freq.,
PnP monitor (normal output)

Bingo!

15. I changed the setting to 32 bit color, I could see normal output
too!

16. I repeated the test again at Althon PC w/ XP booted. Firstly I used
800x600, 16 bit color, test successful. Then I

changed the color to 32 bit with no problem.

17. While my PII PC w/ WinFast 3D L2300 display card still had 800x600,
32 bit color, 60Hz vert. freq., PnP monitor setting

effective, I plugged the NEW 10" MON again to this PC. Bingo! Display
output was normal, no need to change setting to 16 bit

color first.

18. Test finished.

Up to now, I still can't provide a explanation for this strange
behaviour. I only know that lower the color depth first for

this 10" monitor first is a safe setting.

PS: I'm not sure if I had tested WinXP display setting: 800x600, 16 bit
color, 60Hz vert. freq., PnP monitor (messy output) at step 7. But even
if I did, I'd tested it after using 32 bit color setting.