So that the topic does not get too old, I am writing with a similar problem.
I bought
LG Flatron W2453V and connected via DVI cable on the card
ATI 9200SE (D-SUB and DVI output)
and it worked, but when setting up I dug something with the resolution and saw a black screen.
After the reset, unfortunately the monitor showed me a message
"DVI SAVING MODE" .
So I plugged the D-SUB cable and started looking for help on the forums, because the connection via DVI had no effect anymore ...
After many, many combinations, including two monitors,
I managed to make the computer detect two monitors for me,
while connecting the D-SUB and DVI cable at the same time,
however, it does not happen immediately after booting the system, nor through the hardware adding wizard,
but only when I fire up the ATI CATALYST Control Center panel.

Then, after turning on, I hear a sound like turning on a USB device and start "playing": /

At this point, the image is already expanded to include a second "virtual" monitor.
When switching to DVI - unfortunately the picture turns black and that's all good.
I have to reset, and after starting I have the same message as before,
except for DSUB - "DSUB SAVING MODE"
I am trying the "clone desktop" operation so that it does not bother me with the bastard of the extended desktop:

... and I don't know what to do next ...

After switching to a digital monitor, I get a black screen and nothing. After the reset, it reboots as DSUB, but already sees two monitors - digital and analog.

Switching, however, has no effect

I don't know what I'm doing wrong and how do I set this shit to work only in DVI connection mode?
The sterowiniki are pushed up, everything seems bright, but not - black screen and smacked pupa: /
I don't know why, after connecting with a DVI cable alone, the monitor does not work.
I've been struggling with this for a few days now and I'm going crazy!
I really feel like a moron - maybe someone will explain it to me step by step

HELP!