For years I’ve labored under the misconception that “hung” really ought not to be used unless you’re speaking of a man’s…er…naughty bits.
Turns out I was wrong. In all cases save execution, one should use “hung” as both past tense and past participle. Yes, even if you must write something like, “The photograph of David Beckham appeared to be well hung.” (Though I might advise changing “well” to “properly.”)
So. Unless you’re talking about a hanging, in which a convicted criminal has been hanged, stick with hung—no matter how embarrassing it might be.