Mating two assys when one is exploded

Ok.........I think I've found a limitation.

I'm trying to mate one assy to an exploded assy and need it to remain exploded when I'm trying to mate it: on assy "fits" into the other in it's exploded state.

Is this possible? Every time I try to mate, it un-explodes.

Thanks

SW2012 SP1 Win 7 64 bit

SolidworksAssemblies