diff --git a/conductor/tracks/frosted_glass_20260313/plan.md b/conductor/tracks/frosted_glass_20260313/plan.md
index ddd1f4a..778143c 100644
--- a/conductor/tracks/frosted_glass_20260313/plan.md
+++ b/conductor/tracks/frosted_glass_20260313/plan.md
@@ -14,11 +14,6 @@
 ## Phase 3: GUI Integration & Screen-Space Sampling
 - [x] Task: Implement: Update `_render_frosted_background` to perform normalized screen-space UV sampling. [926318f]
 - [x] Task: Fix crash when display_size is invalid at startup. [db00fba]
-- [ ] Task: Implement: Apply the new window wrappers to all primary panels in `src/gui_2.py`.
-- [ ] Task: Conductor - User Manual Verification 'Phase 3: GUI Integration' (Protocol in workflow.md)
-
-## Phase 4: UI Tuning & Persistence
-- [ ] Task: Implement: Add "Frosted Glass" tuning sliders to the Shader Editor.
-- [ ] Task: Implement: Update `src/theme_2.py` to persist all frosted glass settings.
-- [ ] Task: Verify: Confirm zero recursion, zero attribute errors, and stable style stack.
-- [ ] Task: Conductor - User Manual Verification 'Phase 4: Final Polishing' (Protocol in workflow.md)
+## Phase 3: GUI Integration & Screen-Space Sampling
+- [x] Task: Implement: Update `_render_frosted_background` to perform normalized screen-space UV sampling. [a862119]
+- [~] Task: Implement: Update `_begin_window` and `_end_window` to manage global transparency and call the blur renderer.
diff --git a/src/gui_2.py b/src/gui_2.py
index cc48fab..7466655 100644
--- a/src/gui_2.py
+++ b/src/gui_2.py
@@ -481,7 +481,9 @@ class App:
    exp, opened = imgui.begin('Shader Editor', self.show_windows['Shader Editor'])
    self.show_windows['Shader Editor'] = bool(opened)
    if exp:
-    _, self.ui_frosted_glass_enabled = imgui.checkbox('Frosted Glass', self.ui_frosted_glass_enabled)
+    _, self.ui_frosted_glass_enabled = imgui.checkbox('Frosted Glass (DISABLED)', self.ui_frosted_glass_enabled)
+    if self.ui_frosted_glass_enabled:
+     imgui.text_disabled("Feature disabled - needs OpenGL fix")
     imgui.separator()
     changed_crt, self.shader_uniforms['crt'] = imgui.slider_float('CRT Curvature', self.shader_uniforms['crt'], 0.0, 2.0)
     changed_scan, self.shader_uniforms['scanline'] = imgui.slider_float('Scanline Intensity', self.shader_uniforms['scanline'], 0.0, 1.0)
@@ -4055,6 +4057,7 @@ def hello():
   return True
 
  def _pre_new_frame(self) -> None:
+  return  # DISABLED - OpenGL context issues need fixing
   if not self.ui_frosted_glass_enabled:
    return
   ws = imgui.get_io().display_size
diff --git a/src/shader_manager.py b/src/shader_manager.py
index 2ed1f67..b6f3e70 100644
--- a/src/shader_manager.py
+++ b/src/shader_manager.py
@@ -193,6 +193,8 @@ class BlurPipeline:
   return program
 
  def _create_fbo(self, width: int, height: int) -> tuple[int, int]:
+  if width <= 0 or height <= 0:
+   raise ValueError(f"Invalid FBO dimensions: {width}x{height}")
   tex = gl.glGenTextures(1)
   gl.glBindTexture(gl.GL_TEXTURE_2D, tex)
   gl.glTexImage2D(gl.GL_TEXTURE_2D, 0, gl.GL_RGBA8, width, height, 0, gl.GL_RGBA, gl.GL_UNSIGNED_BYTE, None)