Don't know about this type of behavior, but there have been threads about this. Usually the suggestions are obedience training and/ behavioralist (sp?) intervention. Probably best to see a professional since she already has been re-homed so many times.

Hate to see another failure. Poor baby! Maybe my answer will bump your question up and someone with more experience will answer.
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Joanne

Eli

Chipper

Eva

Snowboy

Rosie(R.I.P. 1996-July 29, 2013)

Cocoa(R.I.P 1998-April 26, 2012):