[QuickSilver]

I think some people here have had success tying two baby gates together, but I don't know the specifics, and I'm not sure it would hold if your dog really launched herself at it. Actually, now that I think about it, I think some people have doubled up on the x-pen to prevent their dogs from climbing over the barrier.

It sounds like you guys already spend time in the room, so when are these chase sessions happening? Is she noticing other cues that indicate you are leaving? I would think you could play with going in and out. Walk into the room with her, give her a treat. Close the door when you're inside with her. Close her in by herself, then open the door after ten seconds and walk back in. Etc. It might also help if you close the door and then move around nearby so she can hear that you are still in the house and likely to come back soon.

Also, have you tried giving her treats that involve a lot of attention, like a bone, or a kong, or one of those treat-dispensing puzzles?