diff --git a/lib/kwinglutils.cpp b/lib/kwinglutils.cpp
index 49b94167a6..a01d1788a6 100644
--- a/lib/kwinglutils.cpp
+++ b/lib/kwinglutils.cpp
@@ -1183,11 +1183,6 @@ GLShader *ShaderManager::loadShaderFromCode(const QByteArray &vertexSource, cons
 
 void ShaderManager::initShaders()
 {
-    // HACK: the generic shaders fail with NVIDIA's blob
-    // temporarily disable them to force kwin on GL 1.x profile
-    if (GLPlatform::instance()->driver() == Driver_NVidia) {
-        return;
-    }
     m_orthoShader = new GLShader(":/resources/scene-vertex.glsl", ":/resources/scene-fragment.glsl");
     if (m_orthoShader->isValid()) {
         pushShader(SimpleShader, true);
diff --git a/scene_opengl_glx.cpp b/scene_opengl_glx.cpp
index 4e89664f56..edff792ab8 100644
--- a/scene_opengl_glx.cpp
+++ b/scene_opengl_glx.cpp
@@ -587,6 +587,13 @@ void SceneOpenGL::flushBuffer(int mask, QRegion damage)
                     glXCopySubBuffer(display(), glxbuffer, r.x(), y, r.width(), r.height());
                 }
             } else {
+                // if a shader is bound, copy pixels results in a black screen
+                // therefore unbind the shader and restore after copying the pixels
+                GLint shader = 0;
+                if (ShaderManager::instance()->isShaderBound()) {
+                   glGetIntegerv(GL_CURRENT_PROGRAM, &shader);
+                   glUseProgram(0);
+                }
                 // no idea why glScissor() is used, but Compiz has it and it doesn't seem to hurt
                 glEnable(GL_SCISSOR_TEST);
                 glDrawBuffer(GL_FRONT);
@@ -608,6 +615,10 @@ void SceneOpenGL::flushBuffer(int mask, QRegion damage)
                 glBitmap(0, 0, 0, 0, -xpos, -ypos, NULL);   // move position back to 0,0
                 glDrawBuffer(GL_BACK);
                 glDisable(GL_SCISSOR_TEST);
+                // rebind previously bound shader
+                if (ShaderManager::instance()->isShaderBound()) {
+                   glUseProgram(shader);
+                }
             }
         } else {
             waitSync();