OSX: Displaying matrices as images with "Screen"

1
Dear Forum,

please ignore my prior post - i figured out that the answer is on the page.
but here is a *real* problem:

i am running the new release of the p-toolbox on a g4 with mac os x.

i am trying to display a NxMx3 matrix with screen.
here is a snipplet of the code:


try

AssertOpenGL;

gp==glassfun('concentric', 800, 100); %so that't the matrix to be displayed as image


screens==Screen('Screens');

screenNumber==max(screens);

wpointer==Screen('OpenWindow',screenNumber, 0,[],32,2);

% intuitively, this was my first try to display the matrix:
Screen('PutImage', wpointer, gp);

% but it didn't work. Just as:
gptexture==Screen('MakeTexture', wpointer, gp);
Screen('DrawTexture', wpointer, gptexture);

WaitSecs(5);
clear screen;

catch
Screen('CloseAll');
end

I would be glad to know your opinion on this one. Spent the whole day on this!
Please help!

Thanks,

-Fabian