Hello,
I got that bug last night as well.

I was jumping from scavenge spot to scavenge spot as the distance on a good sprint-jump is roughly the distance to the next scavengable spot. Occasionally if you hold down mouselook (rightclick) for too long it will lock up in mouselook and you must right click before you can see your cursor again. I believe this is what happened when I attempted to scavenge and received a tree in my hand. A felled tree appeared in that slot things such as harvested metal, cloth, leather, plastic does. The tree came out of my characters chest and moved as I did.

Forwarding this issue over to look into further.

I confirm. I was collecting scrap leather, i had the first 4 piles seperated into items, and was just take a rest with "Sit Down Option" when i stand up again and collected the next Leather. But instead of a Leather, a giant Tree appeared in front of me and my backpack showed a grey Box.

28 March, 2011, around 16:30

I asked other People, they all confirmed to see the tree in front of me. I just discarded it now and took severel screenshots. In the Screen you see at the right middle side the inventory box and my mouse over the grey "no image" box show the name of the tree "Felled Weeping Willow"

Well i dont know, i tryed to hang the screenshot here with upload, seems not to work, sorry, dont know how this thing works. I just send it via Bug Mail. Maybe delete this poste here ^^

I scavenged one of these as well. I did not notice right away so I'm not sure of my actions when it occurred. I did not get the graphical glitch though, just the item in my inventory. I just hit 100 scav and I only had this happen once.