Segmentation fault when using subplot and pcolor

I can make a pcolor(x,y,C) map fine for each of 10 different C's. x=[1:100] and y=[1:201] in all cases. The C values are always in the range 0 to 100. When I try to put all maps in one plot using subplot(4,3,i), i=[1:10], I get a segmentation fault. When I change 'pcolor' to 'contour' (and change nothing else in the code), all works well, 10 maps on one plot. When I go back to 'pcolor', segmentation fault. If I plot only 1 of the 10 pcolor maps using subplot (subplot(4,3,i), i=10), that single map shows up perfectly on the plot. If I try 2 pcolor maps, segmentation fault. Any idea of why 'contour' works perfectly but 'pcolor' gives a segmentation fault for the same data?