After upgrading from 12.10 to 13.10 the resolution across dual monitors must be reduced if it is greater than 2400ish.
After installing the gnome-flashback, the desired resolution was obtained on 13.10.
Perhaps we all know about this or perhaps this is the wrong place for this post? I wasn't able to find anything about it.
It turned out my good monitor was stuck in a fairly low-res mode due to this Unity 3d restriction. One monitor is the laptop screen and is shaped differently. This was not a problem for unity 2d on 12.10. After installing unity 2d on 13.10 nothing changed as far as I could tell but perhaps I goofed.
The resolutions currently in use are 1280 x 800 and 1280 x 1024. It seems unity 3d was apparently unhappy with 2560 across the two screens.