Changing the resolution when setting to horizontal span?

Another quick question. Saw it asked it another thread but wasn't answered.

I'm using a new 22" widescreen with my old 19". 8800GT graphics card.

When in dual view everything is fine and I can set the resolutions independently, but as soon as I change to horizontal span my 22" monitor decides to use the same resolution as my 19" (1024x768 ) rather than its usual 1680x1050 and all options relating to resolution in the Nvidia control panel become greyed out. Is there any way to get around this? 1024x768 is craptistic :*(

Thanks in advance.

I have the same problem and I'm quite sure that it isn't possible. Horizontal span seems to always take the lowest resolution and then double it :/
I have the same setup as you, 22"wide (1680x1050) and 19" regular (1280x1024)

^^ See above.