Interactive save still broken in Tkinter

Sorry to bug you about this again.
This is an old problem that hasn’t been fixed yet.
I don’t know how to fix it, but I hope somebody does.

Using Tkinter, in interactive mode, using pylab, after saving by clicking on the save button on Toolbar2, any reference to the figure will have disappeared (although the figure window remains open). So the next plot command will create an entirely new figure.

This bug was started, we think, when we switched to the much nicer filedialog that we are using right now. I would like to keep using the nicer filedialog, but I also would like the bug to be fixed.

Anybody any ideas?

Thanks, Mark