OpenGL renders rectangle instead of text in case of using GLSL

Question

I use my own QGraphicsItem-based class for drawing in QGraphicsScene. I also use FTGL for text rendering. Everything works fine until I start using shaders. My frame update logic is following: in MyGraphicsItem::paint I first update frame with following code (for YUV images):

glEnable(GL_MULTISAMPLE);

QGLFunctions glFuncs(QGLContext::currentContext());

glFuncs.glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_RECTANGLE, tex0Id);
glTexSubImage2D(GL_TEXTURE_RECTANGLE, 0, 0, 0, width, height, GL_LUMINANCE, GL_UNSIGNED_BYTE, data);


glFuncs.glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_RECTANGLE, tex1Id);
glTexSubImage2D(GL_TEXTURE_RECTANGLE, 0, 0, 0, width/2, height/2, GL_LUMINANCE, GL_UNSIGNED_BYTE, data + (width * height));

glFuncs.glActiveTexture(GL_TEXTURE2);
glBindTexture(GL_TEXTURE_RECTANGLE, tex2Id);
glTexSubImage2D(GL_TEXTURE_RECTANGLE, 0, 0, 0, width/2, height/2, GL_LUMINANCE, GL_UNSIGNED_BYTE, data + (int)(5 * width * height) / 4);        

shader->bind(width, height);

and after that I render text:

glDisable(GL_TEXTURE_RECTANGLE);

glOrtho(0, WIDTH, 0, HEIGHT, 0, 1);
glColor3f(0.0, 1.0, 0.0);

bufferFont.Render("This is a text", -1, FTPoint(150, 200, -1.0));

But instead of text there is a rectangle. I tried to disable GL_TEXTURE_2D, but it didn't work. How can I use both shaders and FTGL