Can't create custom resolution on external monitor

[geluidsgolf]

Hello I have bought a external monitor from acer with a resolution of 1366x768
I have a thinkpad t61 with nvidia quadro nvs 140m

The external is nicely identified by the control display of nvidia but when I want to add a custom resolution it doesn't get added to the list. (it's working fine on my primary display).

Does anybody know what can be the problem?

Thanks

[basketb]

Did the monitor come with a driver (file) and have you installed that one?

[geluidsgolf]

It's an Acer x163w screen and it doesn't come with drivers nor can I find any on the internet..

The crazy thing is that when I run moninfo.exe from Entech it gives the following info:

Native/preferred timing.. 1366x768p at 60Hz (16:9)
Modeline............... "1366x768" 85,500 1366 1435 1578 1790 768 771 781 798 -hsync +vsync

So native information 1366x768 is in the EDID or whatever you call it of the monitor..

When I install drivers from Laptopvideo2go.com I can adjust the resolution of my external monitor to 1366x768 but the problem is my primary thinkpad primairy lcd is flickering with these drivers so I have to use the lenovo drivers

[geluidsgolf]

no one out there who can shed some light on the subject?