drawitem problem

Hey, I have problem with drawitem function, here is my code:

Drawing a rectangle function:

function ItemRectangle:draw()

	self.id = drawrect(self.x, self.y, self.w, self.h);

	if(self:getItemId() > 100) then

		setcompositionmode(0)

		self.id = drawitem(self:getItemId(), self:getX()+2.5, self:getY()+2.5, 100, math.min(math.max(1,self:getItemCount()), 100), -1)

		setcompositionmode(3)

	end

end 

and in a script:

setfillstyle('gradient', 'linear', 2, 0, 0, 0, 36)

addgradcolors(unpack(colorItem));

for _,v in pairs(itemRects) do

	v:draw();

end

it looks like:
http://i.imgur.com/9WIJppd.png

OK, it seems good. but when I reset itemid and drawitem is not executed anymore, one of rectangles gets invisible (only border is visible):
http://i.imgur.com/giLhRNK.png

when I set itemid back, it is still invisible:
http://i.imgur.com/aNEgRdm.png


I am confused and dont know why it behaves like this. gradient should be visible