I am having a little trouble with a Max 7219 controlling an 8 x 8 LED matrix. I have previously constructed one as a hardwired cicuit so I know that the code and circuit schematic (Nick Gammons) are good.
If you have the 2x MAX7219 chips wired as per my clock schematic then the ScrollTest2.ino posted above is configured for a pair of MAX7219 chips and should work okay.