James, - It's always possible that this could be another Windows 7 peculiarity, but, with reference to dual monitor video cards...
then you should go into Windows Display Properties/Settings, and set the video card for Single Display. - When you then go to the MA3 Display Settings, you will
not see two monitor tabs, or the, 'Render same image on all monitors', option.... And everything should then work as a normal single monitor setup, with MA3 scrolling as intended.
I went into settings however there does not appear to be an option to output 1 monitor from the card.
As long as it works it is fine it just means having to check boxes in MA3 that would not normally have to be checked.
XP never had those boxes checked so it may very well be a Windows 7 oddity.
Maybe once Jim goes to 7 he will see how to proceed.