Deleting a layout sketch block?

Hello,

Using SolidWorks 2011 SP4.0

Imagine a block created in an assembly from a layout sketch. If the last instance of the block is deleted from the sketch it is still in the insert block menu. I can't find a way to delete it.

If a block is created in a normal (non-layout) sketch, it disappears from the insert blocks window when the last instance is delted from the sketch. This make sense, but I'm confused as to why that does not work for a block from a layout sketch.

How can a block that was created in a layout sketch be deleted?

Thanks for any insight,

Dave

SolidworksAssemblies