Screen is 1928 x 1208 instead of 1920 x 1200

As I have a 512 MB nVIDIA GeoForce 8800GT I posted about the
following problem in the nVidia newsgroup a few months ago, but it remains
unsolved. It was suggested then by someone that it was probably a hardware
problem. Posting in a couple of hardware groups yesterday, I've had
suggestions that it's probably a software or graphics card driver problem!

Anyway, I'm now finally fed up with it and determined to find a fix. Hence
my post here in case it's an OS problem please.

--------------------

My XP Pro PC has an Iiyama Prolite E2403WS 24" widescreen monitor,
connected with the recommended DVI input. Screen resolution is set in the
usual way to 1920 x 1200. But for any maximised window the actual size is
1928 x 1208 and the position is always -4,-4.

You can't adjust it with the physical monitor settings, which is only
possible for analog connection mode, not DVI.

Under Properties, the driver for the monitor is shown as
C:\WINDOWS\system32\spool\drivers\color\PLE2403WS. ICM

I tried updating that but it made no difference.

My nVidia driver is pretty recent, and anyway the problem has been present
for nearly 3 years, across several versions.
FWIW, here's an extract from Software information in the nVidia control
panel:
Performance: 6.02.15
nForce package version: Not reported
nForce networking: 67.67 (1.00.02.06767)
GeForce video: 257.21 (6.14.12.5721)
nForce IDE: 9.98 (5.10.2600.0998)
nForce audio: Not reported
Microsoft DirectX: 9.0c (5.3.260 .2180)

I also tried changing from '1920 x 1200(Native)' to 1920 x 1200 custom in
the nVidia Control Panel, using the Customise option. No difference. I
then even tried 1912 x 1192 to see if I could 'compensate' for those extra
8 px that appear to be getting added. But it wouldn't stick. Gone back to
'native' 1900 x 1200.

Any help in discovering where those extra 8 horizontal and vertical pixels
are coming from, and removing them, would be much appreciated please.

--
Terry, East Grinstead, UK