Disabling Group Separation

I'm using group separation for ground units as a method to space out swarms of units. The problem I'm having is when a unit dies, its corpse starts sliding around because its Group Separation isn't turned off when it dies. Is there any way to disable it?

Uhh, check when a unit is selected, and if it is dead, remove it from the current selection? Or when a unit dies, give it locust? (If you can give dead units locust, that is)

He's talking about how flying units spread out when bunched together.

If your map has no way to revive units, replace the corpse with a different unit. (One that won't move)

Oh, woops. Sorry then.

make unit explode on death...