Max72xxPanel library

I spent a considerable amount of time yesterday trying to trouble shoot this. I probably should have been more descriptive in my initial post. My setup is 2 sets of 8 8x8 matrices stacked one on top of the other to make a 16x64 matrix. The first display is the bottom left and this is the one connected to the Arduino. The 8th display is connected to the top left matrix. I had tested the setup with a 8x64 and it would work just fine.

Currently if i edit

matrix.drawLine(x, 16, x, 16 - y, HIGH);

to

matrix.drawLine(16, 16, 16, 0, HIGH);

the lower half of the display correctly draws a line from the first column of the third display to the top but the top half which I would expect to behave similarly (first column on the 11th display) to be lit up instead has the last column of the 10th display on.

I haven't tried Parola. Does anyone know if it supports simple graphics primitives such as a line?

Again would much appreciate if someone can point me in the correct direction. I am happy to invest time in trying to modify the library, but a pointer to the correct place would help immensely.

Thanks
Nitin