Well, I'm not 100% sure, but it could be one of two things. The Windows 7 driver for your monitor doesn't support that Frequency, or that the windows seven GUI is just more graphically demanding then XP's GUI.
Take a look at Link Removed . I know it is not 7 specifically but the registry in my experience has not changed much. You may be able force the change by modifying the registry.
I'd try running Windows Updates and see what turns up.. Mind you 85Hz isn't too bad for a CRT and as long as it's way above 60 you won't notice the difference anyway..
I tried many Times, and it was never working. I could make the test, but after it was writing only 85 Hz to the "Custom List".
................. But .....................
Now... i made it...
> Changed the monitor Type to "Generic Non Plug&Play Monitor"
> nVidia Systemsteuerung
> Change Resolution (Auflösung ändern)
> Custom (Anpassen)
> Then choose all your desired Resolutions with the GFT Timing and Test. After the Test is successfull, the Resolution and the right Refresh Rate is writed in the list. (Alle gewünschten Auflösungen und Bildwiederholungsraten mit manuellen "GFT-Timings" eintragen, testen. Wenn der Test erfolgreich war, wird diese Auflösung und die Hz-Zahl in die Benutzerdefinierte Liste eingetragen.
> Go on, until you wroted all... after the last, save it. (So tragt ihr dann alle ein, die ihr wollt.)
> Then choose one of the new Resolution just there and it will work. (Dann wählt ihr dann gleich eine der neuen Auflösungen. Es werden alle funktionieren.)
Now, you can choose them all...
Now, i can try my 3D vision..., which came today.
PS. i think, this is a extra Tour btw. Microsoft and nVidia... with the new glasses, you can only use it from Vista or 7. And now, because all people change to 7, the made, that CRT's can't go higher then 85Hz, so you can't use the 3D glasses with them..., ... they wanna make you buy a expensive new LED ...
I play with my Eizo F931, 21"and my Elsa 741, 22". My W900 won't go so high in refresh rate. Only at deeper res. (it costed only 1 $). Next days, i will go to take my FW900. I hope it will have higher resolutions. I use 2 with a 4 Port Dual View KVM Switch. Seems, that i have to play 3D only on 4:3 or 5:4, until the FW900 is here.
I hope, this solution helps also for you... but... don't forget. It was here only working, because i changed the Monitor type to Generic non plug&play, ... i think, so the EDID will not activatet. Or... which it's name is...