Some photos of the trees might offer some clues. You can upload the photos to imageshack.us for free without sigining up and we can take a look. Be sure to include a photo showing the base of the tree and the ground.

I'll try to get some this evening.

I had some 3 year old questions, too, but I've forgotten what they were . . .*

Agree that photos would help. Possible causes include root self-strangulation (coiled roots from a potbound plant, which circle round the trunk and strangle it as they thicken with growth), deep planting (burying the tree too deep for the roots to get the surface soil aeration they need), and fungal disease (some decay fungi in the roots of the old tree might be pathogenic enough to kill the new tree).

Resin

* Sorry, couldn't resist! ;-)

I'll try to post pics...sounds like it could be impossible to tell.

Your pictures are here

http://forums2.gardenweb.com/forums/load/trees/msg0720163111497.html?1

Here is a link that might be useful: the pictures