Windows 7: No Native Resolution 8600GT + 933SN

(First of all, sorry for my english)

Hi people, this is mi problem:

I have a Geforce 8600 GT connected with analogic VGA to a Samsung 933SN 18.5" monitor. The native resolution is 1360x768 and it does not appear on the Windows Resolution Screen. I tried updating and downdating Graphic Card and Monitor's drivers and nothing, also I have the last updates from Microsoft. I tried forcing it with PowerStrip but nothing happened (PowerStrips says that the max resolution is 1360x768, so sweet). I search at Windows Registry for the max resolution admited, and it appears 1360x768, just what I want, near the details of the monitor drivers details; still does not appear as an option in Windows. 1280x1024 is the max resolution and 1280x768 seems the best option now (It appears as native resolution), but it's still a great difference.

Any suggestions please?

Gustavo.