At least for me (Debian Squeeze + Xorg from backports on Intel GM965/GL960 gfx) the background of the automation editor is not redrawn properly. It appears transparent with all drawing from the x-hair cursor etc left as artifacts...
This tiny patch fixes the issue for me:
diff --git a/src/gui/AutomationEditor.cpp b/src/gui/AutomationEditor.cpp
index 3a597e7..21d704b 100644
--- a/src/gui/AutomationEditor.cpp
+++ b/src/gui/AutomationEditor.cpp
@@ -1256,7 +1256,7 @@ void AutomationEditor::paintEvent( QPaintEvent * _pe )
// start drawing at the bottom
int grid_bottom = height() - SCROLLBAR_SIZE - 1;
- p.fillRect( 0, TOP_MARGIN, VALUES_WIDTH, height() - TOP_MARGIN,
+ p.fillRect( 0, TOP_MARGIN, width(), height() - TOP_MARGIN,
QColor( 0x33, 0x33, 0x33 ) );
// print value numbers
Which version of Qt is this? Just asking because in AutomationEditor::paintEvent() there's a call
style()->drawPrimitive( QStyle::PE_Widget, &opt, &p, this );
which (re)draws the whole background. I never experienced problems with it. Does this always happen? Do you have compositing enabled?