Unity 4.6 and Grabpass fails

I am using Unity 4.6 and the GrabPass feature and I would like to know if it’s possible to use GrabPass ans Opaque RenderType because it doesn’t seem to work…

GrabPass
{ "_Grab" }

Tags { "Queue" = "Geometry" "RenderType" = "Opaque" }
LOD 400

CGPROGRAM
#pragma target 3.0
#pragma surface surface Lighting fullforwardshadows
(...)

When adding the opaque RenderType, the shadows are available but the GrabPass not… when removing the RenderType, the GrabPass appears as a silhouette and I want to mask it.

Is it possible to use masked GrabPass and shadows in deferred rendering ?
Thanks a lot !

Have you tried moving the Queue to a later point in the rendering process?

"Queue" = "Geometry+1"

might be enough to keep the object technically opaque and not wait too long before rendering it into the scene.