If you use compiz and set the dash/panel Blur effect to None instead of STATIC or DYNAMIC, the panel's transparency gets back to normal, yet the dash's transparency gets screwed (becomes fully transparent).
For now, with STATIC and DYNAMIC BLUR, I cannot get a semi transparent panel, unless I set Opacity to 0.0.
If you use compiz and set the dash/panel Blur effect to None instead of STATIC or DYNAMIC, the panel's transparency gets back to normal, yet the dash's transparency gets screwed (becomes fully transparent).
For now, with STATIC and DYNAMIC BLUR, I cannot get a semi transparent panel, unless I set Opacity to 0.0.